The most common presentation is orthostatic hypotension [9]. Symptoms may be mild, but can be disabling. Patients with POTS may develop true syncope. Sometimes, other autonomic symptoms may prevent prior to POTS. These may include anhidrosis, dry mouth or dry eyes. Also, bowel and bladder dysfunction are common in addition to impotence or ejaculatory dysfunction.

A detailed family history is important to help identify an inherited form of disease. Symptoms may be very subtle in family members and may require careful questioning to identify. In addition to careful history, physical examination is important. A drop in BP from sitting to standing more than 30 mm Hg is diagnostic of orthostatic hypotension. Motor examination is also important because a somatic peripheral neuropathy is frequently associated with an autonomic neuropathy.

• Amyloidosis

  Nine of the patients had AL amyloidosis, two had familial amyloidosis associated with a transthyretin abnormality, and one was untyped. The pupils were abnormal in all 12 patients. [ncbi.nlm.nih.gov]

  Causes include diabetes, amyloidosis, autoimmune disorders, cancer, excessive alcohol consumption, and certain drugs. [merckmanuals.com]

  nausea, heart rate abnormalities, light headedness, urination, and erectile dysfunction The risk factors for Autonomic Neuropathy include diabetes, obesity, high blood pressure, and the development of conditions such as cancer, hypothyroidism, and amyloidosis [dovemed.com]

• Heat Intolerance

  The symptoms depend upon what organs are affected and may include abdominal swelling, heat intolerance, nausea, vomiting, impotence, diarrhea, constipation, dizziness with standing, difficulty urinating and urinary incontinence. [medicinenet.com]

  Symptoms of Autonomic Neuropathy General symptoms of this condition may include: Inability to sweat properly, leading to heat intolerance Loss of bladder control, leading to infection or incontinence Dizziness, lightheadedness or fainting because of a [stanfordhealthcare.org]

  intolerance brought on with activity and exercise Sexual problems, including erection problems in men and vaginal dryness and orgasm difficulties in women Small pupil in one eye Weight loss without trying Exams and Tests Signs of autonomic nerve damage [pennstatehershey.adam.com]

  In this way, it is important that sufferers of the symptoms described seek medical attention as soon as problems arise and look out for any other unusual occurrences such as sweating too much, heat intolerance, sexual problems, or unintended weight loss [healthery.com]

  intolerance brought on with activity and exercise Sexual problems, including erection problems in men and vaginal dryness and orgasm difficulties in women Small pupil in one eye Weight loss without trying Signs of autonomic nerve damage are not always [medlineplus.gov]

• Hypothermia

  Changes in the body's ability to regulate temperature may make you more prone to body chilling (hypothermia) or heat-related illness, such as heatstroke or heat exhaustion. [uofmhealth.org]

  They are also predisposed to intraoperative hypothermia. Furthermore, autonomic dysfunction contributes to delayed gastric emptying, putting patients at risk for aspiration of gastric contents. [openanesthesia.org]

  Temperature regulation Hypothermia and hyperpyrexia can result from disruption of the various temperature regulatory mechanisms. Sweating, shivering and vasoactive reflexes can be affected. Face Pallor. Reduced or absent sweating. [patient.info]

• Bradypnea

  […] of heart rate (tachycardia, bradycardia), orthostatic hypotension, inadequate increase of heart rate on exertion Respiratory system: impairments in the signals associated with regulation of breathing and gas exchange (central sleep apnea, hypopnea, bradypnea [en.wikipedia.org]

• Constipation

  KEYWORDS: Abdominal pain; Autonomic neuropathy; Constipation; Diarrhoea; Gastric electrical stimulation; Gastroparesis [Indexed for MEDLINE] Free full text [ncbi.nlm.nih.gov]

  Constipation If just looking at relief of constipation as the primary outcome measure, relatively efficient laxative therapy has long been available [ 21 ]. [link.springer.com]

  Add fluid and fiber to your diet to prevent bloating and constipation. Laxatives can help with constipation, and other medicines can treat diarrhea and belly pain. Sleep with the head of your bed raised to prevent heartburn. [webmd.com]

  Digestive system Damage to the nerves of your digestive system can cause symptoms such as the following: bloating, fullness, and nausea constipation diarrhea, especially at night diarrhea alternating with constipation fecal incontinence problems swallowing [niddk.nih.gov]

• Nausea

  Early symptoms might include: Becoming faint or lightheaded when standing Changes in bowel, bladder, or sexual function Unexplained nausea and vomiting when eating Early diagnosis and treatment may control symptoms. [pennstatehershey.adam.com]

  This may cause frequent bloating, belching, heartburn, nausea, or vomiting. Diarrhea, because of abnormally fast passage of waste through the intestines. Diarrhea is more common at night. Belly pain. [uofmhealth.org]

• Delayed Gastric Emptying

  RESULTS: Chronic alcoholics had increased dyspepsia, delayed gastric emptying and oro-cecal transit time but faster gallbladder emptying, with slightly accelerated colonic transit. [ncbi.nlm.nih.gov]

  Clinically observed complications such as diabetic diarrhea, delayed gastric emptying, [jamanetwork.com]

  Furthermore, autonomic dysfunction contributes to delayed gastric emptying, putting patients at risk for aspiration of gastric contents. [openanesthesia.org]

  These revealed delayed gastric emptying with food debris, no pyloric stenosis, and fluid filled loops of small bowel. [pmj.bmj.com]

• Abdominal Bloating

  This can result in symptoms such as abdominal bloating, nausea, heartburn and unpredictable changes in blood glucose levels. [diabetes.co.uk]

  Changes in digestive function due to autonomic neuropathy can lead to symptoms such as feeling full after a few bites of food, loss of appetite, diarrhea, constipation, abdominal bloating, nausea, vomiting, difficulty swallowing and heartburn. [medicalxpress.com]

  When this occurs, numerous symptoms may evolve, such as blurry vision, constipation or diarrhea, inability or reduced ability to sweat, abdominal bloating and difficulty during urination. [livestrong.com]

• Dysphagia

  In both families, patients had severe muscle atrophy and weakness in limbs, limb girdle, and face; sensory impairment in the distal limbs; dysphagia, episodic intestinal pseudoobstruction with vomiting attacks; and urinary and fecal incontinence. [ncbi.nlm.nih.gov]

  Impaired motor control with dysphagia was interpreted as reduced muscle power and prompted an early diagnosis of Guillain-Barre syndrome. Symptoms progressed for a few days and later stabilized. [n.neurology.org]

  Neurogenic bladder is a broad term used to describe this dysfunction.[1] Gastrointestinal tract: dysphagia, abdominal pain, nausea, vomiting, malabsorption, fecal incontinence, gastroparesis, diarrhea, constipation Cardiovascular system: disturbances [en.wikipedia.org]

  Bloating, Loss of appetite, Early satiety, Postprandial vomiting Bladder dysfunction : Frequency, Urgency, Nocturia, Hesitancy, Weak stream, Dribbling, Urinary incontinence, Urinary retention Exercise Intolerance Esophageal dysfunction : Heartburn, Dysphagia [diapedia.org]

• Hypotension

  We present a unique case of orthostatic hypotension as the sole feature of a CRMP-5 paraneoplastic autonomic neuropathy in a patient with small cell lung cancer. [ncbi.nlm.nih.gov]

  People with orthostatic hypotension are advised to avoid sitting up or standing up suddenly; wear compression stockings; avoid medications that aggravate orthostatic hypotension, such as tricyclic antidepressants; eat small, frequent meals; and drink [diabetesselfmanagement.com]

  Patients have an orthostatic intolerance characterized by hypotension and tachycardia. In severe cases, patients may experience syncope. Pandysautonomia. [symptoma.com]

• Orthostatic Hypotension

  We present a unique case of orthostatic hypotension as the sole feature of a CRMP-5 paraneoplastic autonomic neuropathy in a patient with small cell lung cancer. [ncbi.nlm.nih.gov]

  People with orthostatic hypotension are advised to avoid sitting up or standing up suddenly; wear compression stockings; avoid medications that aggravate orthostatic hypotension, such as tricyclic antidepressants; eat small, frequent meals; and drink [diabetesselfmanagement.com]

• Tachycardia

  Patients presented with multiple different autonomic disorders, including postural tachycardia syndrome, gastrointestinal dysmotility, and complex regional pain syndrome. [ncbi.nlm.nih.gov]

  The most common form of autonomic neuropathy is postural orthostatic tachycardia syndrome (POTS). [symptoma.com]

  Healthy subjects develop tachycardia and peripheral vasoconstriction during strain and an overshoot bradycardia and rise in blood pressure with release. The ratio of longest R-R shortest R-R should be > 1.2. [medscape.com]

• Irregular Heart Rhythm

  Your health care provider may recommend: Extra salt in the diet or taking salt tablets to increase fluid volume in blood vessels Fludrocortisone or similar medicines to help your body retain salt and fluid Medicines to treat irregular heart rhythms Pacemaker [pennstatehershey.adam.com]

  For more serious cases, it might be recommended that patients take fludrocortisone or similar drugs in order to help the body retain salt and fluid, have a pacemaker installed, or take medicines designed to treat irregular heart rhythms. [healthery.com]

• Decreased Sweating

  Decreased sweating may be evident on examination. For example, on a very warm day if the socks are very dry this likely represents decreased sweating. 4. [americanautonomicsociety.org]

  Further, HSAN-4 is accompanied by decreased sweating and intellectual disabilities. [ncbi.nlm.nih.gov]

  Autonomic neuropathy can also prevent with increased/decreased sweating. If this is troublesome, there are medications that will diminish symptoms. [symptoma.com]

  […] libido Gastrointestinal dysfunction: intermittent diarrhea, constipation, nausea, vomiting, full-ness after eating little, loss of appetite, slowing of gastric content, bloating, heartburn Impaired sweating: excessive or decreased sweating Exercise intolerance [my.clevelandclinic.org]

• Night Sweats

  It can lead to many different symptoms, like dizziness, night sweats, and constipation. Those nerves are part of your autonomic nervous system. [webmd.com]

  Night sweats or sweating while eating also may occur. [stanfordhealthcare.org]

  Sweating Damage to the nerves that control sweating means that the person has trouble regulating body temperature; night sweats or sweating while eating also may occur. [columbianeurology.org]

  Sweat glands The symptoms of AN that affect your sweat glands can include dry skin on your feet and excessive sweating or lack of sweating. [healthline.com]

• Suggestibility

  In addition, anecdotal experience has suggested that antithrombotic therapy and intravenous immunoglobulin therapy may result in significant clinical improvement in these patients. [ncbi.nlm.nih.gov]

• Dizziness

  Early symptoms of AN include dizziness or faintness when rising or standing, and vomiting or feeling nauseated when eating. You may also have disturbances in bowel movements, bladder control, or sexual functioning. [healthline.com]

• Peripheral Neuropathy

  Autonomic nerve fibers are affected in most generalized peripheral neuropathies. [ncbi.nlm.nih.gov]

• Dysautonomia

  Föredragen term Riley-Dayin oireyhtymä Hänvisningstermer dysautonomia familialis familiaalinen dysautonomia familiaarinen dysautonomia familjär dysautonomi (Riley-Day) Riley-Day Riley-Dayin syndrooma Riley-Dayin tauti Riley-Dayn tauti suvuittainen dysautonomia [finto.fi]

  We, therefore, propose a Turkish variant of familial dysautonomia in these 2 patients. [ncbi.nlm.nih.gov]

  The primary symptoms in individuals with dysautonomia include Causes [ edit ] Dysautonomia may be due to inherited or degenerative neurologic diseases (primary dysautonomia) [4] or it may occur due to injury of the autonomic nervous system from an acquired [en.wikipedia.org]

  HSN Type I HSN Type II Neurogenic Acroosteolysis Neuropathy Hereditary Sensory and Autonomic Type 1 Progressive Sensory Neuropathy Recessive Form Hereditary Sensory Radicular Neuropathy Type 1 Hereditary Sensory Autonomic Neuropathy Type 2 Familial Dysautonomia [lsd-project.jp]

  He presented this lecture in 2011 at a dysautonomia symposium at St. Luke's Episcopal Hospital in Houston. Additional Resources AAG Research Study Now Recruiting Medical Journal Articles on AAG Dysautonomia International Webchat on AAG with Dr. [dysautonomiainternational.org]

• Guillain-Barré Syndrome

  During episodes, presentation may mimic Guillain-Barré syndrome Guillain-Barré syndrome. Antibodies are produced to gangliosides resulting in an autonomic neuropathy. Lambert-Eaton myasthenic syndrome. [symptoma.com]

  syndrome, autoimmune autonomic ganglionopathy, acute sensory neuropathies Keyword: 急性自律神経性感覚性ニューロパチー, 急性自律神経ニューロパチー, ギラン・バレー症候群, 自己免疫性自律神経節障害, 急性感覚性ニューロパチー, acute autonomic and sensory neuropathy, acute autonomic neuropathies, Guillain-Barré syndrome [webview.isho.jp]

  In a crisis situation, as in the onset of Guillain-Barré syndrome, plasma exchange, intravenous immunoglobulin, and steroids may be given. [medical-dictionary.thefreedictionary.com]

  Autonomic neuropathy may be seen with: Alcohol abuse Diabetes (diabetic neuropathy) Disorders involving scarring of tissues around the nerves Guillain Barré syndrome or other diseases that inflame nerves HIV/AIDS Inherited nerve disorders Multiple sclerosis [pennstatehershey.adam.com]

  Examples include Sjögren syndrome, systemic lupus erythematosus, rheumatoid arthritis and celiac disease. Guillain–Barré syndrome is an autoimmune disease that happens rapidly and can affect autonomic nerves. Diagnosis[edit] This section is empty. [en.wikipedia.org]

• Headache

  The headaches are what they call 'coat hanger' headaches along the shoulders and up into the head. We are in Northern Ireland and The only help we could get was from the Sarah Mattison Trust in London. [medhelp.org]

  She was given a single dose of Sandostatin LAR and within 2 weeks reported the development of increasingly frequent and severe headaches. [ncbi.nlm.nih.gov]

  Results: A 21-year-old woman of Mediterranean descent presented with pulsatile tinnitus (PT) and daily headaches. Fundoscopic exam and visual field testing were normal. [n.neurology.org]

  Side effects can include diarrhea, dry mouth, urinary retention, blurred vision, changes in heart rate, headache, loss of taste and drowsiness. [mayoclinic.org]

  Headaches Many headaches especially those that involve the rear of the skull (occiput) are the result of inadequate blood and oxygen delivery into the muscles of the scalp (known as coat hanger pain). [drbuckeye.com]

• Urinary Incontinence

  OBJECTIVE: This study evaluated associations among cardiovascular autonomic neuropathy (CAN), female sexual dysfunction (FSD), and urinary incontinence (UI) in women with type I diabetes mellitus (T1DM). [ncbi.nlm.nih.gov]

  incontinence Antibiotics may be prescribed to help treat bacterial infections and catheterization may be appropriate in people suffering from urinary incontinence. [diabetes.co.uk]

  Urinary incontinence also may develop because a person may not be able to sense when the bladder is full. [columbianeurology.org]

• Vaginal Dryness

  Vaginal dryness: A woman may have problems with vaginal dryness, arousal or orgasm. Vision-Related Symptoms of Autonomic Neuropathy Autonomic neuropathy also can affect the pupils of the eyes, causing the eyes to adapt slowly to changing light. [stanfordhealthcare.org]

  dryness, decreased libido Gastrointestinal dysfunction: intermittent diarrhea, constipation, nausea, vomiting, full-ness after eating little, loss of appetite, slowing of gastric content, bloating, heartburn Impaired sweating: excessive or decreased [my.clevelandclinic.org]

  (For women) When I have sex, I have problems with orgasms, feeling aroused, or I have vaginal dryness. About my heart and blood vessels I get dizzy if I stand up too quickly. I have fainted after getting up or changing my position. [diabetes.org]

  dryness and orgasm difficulties in women Small pupil in one eye Weight loss without trying Exams and Tests Signs of autonomic nerve damage are not always seen when your doctor examines you. [pennstatehershey.adam.com]

• Urinary Retention

  Four patients had urinary retention and two had voiding difficulty as the initial presentation. Patients with retention became able to urinate within a week (two to seven days). [ncbi.nlm.nih.gov]

  Signs and symptoms[edit] The signs and symptoms of autonomic neuropathy include the following:[citation needed] Urinary bladder conditions: urinary incontinence or urinary retention which happens due to the uncoordinated contraction of the bladder. [en.wikipedia.org]

  Symptoms Symptoms of AAG can include: -severe neurogenic orthostatic hypotension (very low blood pressure upon standing) -fainting -constipation and GI dysmotility -urinary retention (neurogenic bladder) -fixed and dilated pupils (Adie's pupils) -dry [dysautonomiainternational.org]

  […] incontinence, Urinary retention Exercise Intolerance Esophageal dysfunction : Heartburn, Dysphagia for solids Male Sexual Dysfunction : Erectile dysfunction, Decreased libido, Abnormal ejaculation Resting Tachycardia Diabetic Diarrhea: Profuse and watery [diapedia.org]

• Overflow Incontinence

  Overflow incontinence can result from detrusor underactivity. Consider a trial of a cholinergic agonist, such as bethanechol, in patients with urinary retention. [mdedge.com]

  They may include: - A drop in blood pressure on standing (orthostatic hypotension), which can cause dizziness and fainting - Trouble with urination, including diminished sensation, overflow incontinence and inability to empty your bladder completely, [dailystrength.org]

  Finally, overflow incontinence occurs because of denervation of the external and internal sphincter ( 129, 130 ). [care.diabetesjournals.org]

• Bladder Distention

  A grossly overdistended bladder should be drained by catheter to improve contractility, and the patient should be instructed to void by the clock rather than waiting for the sensation of bladder distention. [care.diabetesjournals.org]

• Complete blood count (CBC), basic metabolic panel (BMP), liver function test
• Immunoelectrophoresis
• Glucose tolerance test to evaluate for DM.
• SS-A and SS-B for Sjögren syndrome
• AChR autoantibodies. Anti-ganglionic acetylcholine receptor
• Genetic tests. Specific genetic testing can evaluate for some familial forms of autonomic neuropathies.
• Testing for infections, non-specific inflammatory diseases, autoimmune diseases, or malignancies that could produce a paraneoplastic syndrome.
• CSF. Elevation of CSF protein on lumbar tap can indicate pandysautonomia (along with elevation of CSF enolase that may indicate damage to the dorsal root ganglia). In HIV, there may be elevated CSF protein along with pleocytosis.
• Nerve conduction studies. EMG, electromyography, may confirm a presynaptic neuromuscular defect.
• Thermoregulatory sweat test (TST) and quantitative sudomotor axon reflex test (QSART) are used to evaluate the thermoregulatory pathways [13]. Using alizarin red powder, which changes from orange to purple with moisture, photography maps areas of anhidrosis where the color did not change [14].
• Pupillometry is being investigated as a test for autonomic neuropathy [15].
• Sympathetic skin responses (SSR). Using routine EMG, SSR identifies sweat production by looking for changes in skin conductance in response to electric stimuli.
• Quantitative direct and indirect test (QDIRT). QDIRT tests sudomotor function. A silicone impression of the skin is made while the patient is sweating. Then, the water in the silicone cast can be quantified [16].
• Vascular studies. Duplex imaging can evaluate the arterial and venous systems. In addition, percutaneous oxygen measurements can be informative.
• Urologic studies. Urodynamics are used to assess the genitourinary system [17]. In particular, it is important to measure the post-void residual volume in the bladder. This can be done using ultrasonography.
• GI studies. Gastric and esophageal motility can be examined. Video fluoroscopy or a barium swallow will evaluate for esophageal motility disorders. Gastric motility can be assessed with UGI or with radioisotope methods. Small bowel may be assessed with UGI follow through. Colon motility can be determined via measurement of transit time [18].

• Hypoglycemia

  The HRV parameter low frequency (LF) was significantly (P = 0.029) reduced during hypoglycemia. Changes in LF during hypoglycemia were not different between patients with and without CAN, -0.64 versus -0.48 log(LF) (P = 0.74). [ncbi.nlm.nih.gov]

  Ability to feel symptoms of hypoglycemia Autonomic neuropathy can cause hypoglycemia unawareness, meaning that you don’t feel the symptoms of low blood glucose. [niddk.nih.gov]

  Effect on autonomic neuropathy in diabetes and on hypoglycemia symptoms Autonomic neuropathy has negative effects on hypoglycemia symptoms. Hypoglycemia is when blood sugar drops really low, causing shakiness, dizziness, headaches and even fainting. [azneuromod.com]

  Research suggests that preventing all hypoglycemia for ~3 weeks will allow the individual to regain their hypoglycemia awareness.48 Hypoglycemia awareness training programs may aid people with this complication. [doctorlib.info]

The first goal of treatment is to identify possible underlying causes and begin their treatment. For example, with diabetic neuropathy it’s important to obtain careful control of glucose. In the setting of autoimmune disorders, use of immunomodulatory drugs is indicated. However, in many cases, there is no specific therapy to treat the disease.

In cases where underlying disease is not identified or not treatable, intervention is focused on addressing symptoms. For example with POTS, therapy is focused on increased fluid intake and taking care to avoid falling. By increasing fluid and salt intake, blood volume is increased. Alcohol is to be avoided as it can lead to dehydration. Then, patients should be instructed to slowly move from lying to sitting, and from sitting to standing positions. This allows time for body to equilibrate. Also, patients need to take care that when standing, they have support available to avoid falling and causing injury. When treatment is unsuccessful, pharmacological intervention may help with POTS.

Medications

• Sympathomimetric agents. Midodrine (ProAmatine) may help in treatment of POTS.
• Mineralocorticoids. Fludrocortisone (Florinef) is also used to treat POTS.
• Beta-adrenergic blocker. Metoprolol (Lopressor, Toprol XL) is sometimes used to address the tachycardia associated with POTS. However, care must be taken because it will also lower the blood pressure.
• Colony-stimulating factor. Epoetin alfa (Epogen, Procrit) causes an increase in red blood cell production. With increased hematocrit, symptoms of POTS may be lessened.
• Acetylcholinesterase inhibitor. Pyridostigmine (Mestinon) will help with cases of POTS.
• Anticholiinergic agents. Oxybutynin (Ditropan) and Tolterodine (Detrol) are used in the cases of difficult bladder emptying.
• Vasopressin analogues. Desmopressin acetate (DDAVP) as a nasal spray will decrease nocturnal urinary production.
• Cholinergic agents. Bethanechol hydrochloride (Duvoid, Urecholine) affect smooth muscle to help bladder emptying.
• Phosphodiesterase inhibitors. Sildenafil (Viagra) is effective for treatment of erectile dysfunction by stimulating smooth muscle of corpora cavernosa.
• Neuromusclar blocker. Botulinum toxin type A (Botox) helps in patients with hyperhidrosis.
• Anticholinergic agent. Glycopyrrolate (Robinul) is also used to treat hyperhidrosis.
• Immune globulin. IV immune globulin can be used for autoimmune causes of autonomic neuropathy.
• Anti-inflammatory agent. Prednisone may be helpful in suppressing inflammatory response in a case with presumed autoimmune pathophysiology.

Most cases are idiopathic and demonstrate a very slow progression. For others, prognosis depends on the underlying disease process causing the neuropathy. In many cases, addressing the underlying problem, such as controlling diabetes, eliminating alcohol, or treating other diseases can improve symptoms. For those presenting with an acute idiopathic disease, such as pandysautonomia or Guillain-Barré syndrome, prognosis is excellent after resolution of the acute disease.

Autonomic neuropathy may be idiopathic, or may be part of a familial disease. In addition, secondary autonomic neuropathy may be the result of a number of different disorders, including diabetes mellitus, amyloidosis, autoimmune disorders, or viral infections. The most common neuropathy is that associated with diabetes. Infections can trigger an autoimmune reaction that results in the destruction of autonomic nerves. A similar problem occurs with Guillain-Barré syndrome. Other causes of autonomic neuropathies include cancer, drugs, alcohol, and toxins.

Overall, there is not a significant age, sex, or ethnic predilection for autonomic neuropathies. However, one common presentation is with postural orthostatic tachycardia syndrome (POTS), which is primarily seen in women.

The pathophysiology of autonomic neuropathies depends on the etiology of the disease. Although uncommon, there are a number of inherited autonomic neuropathies. Of the acquired autonomic neuropathies, there are both primary or idiopathic presentations and those that are secondary to other disease processes. Below, we outline some of these diseases.

Inherited autonomic neuropathies

• Familial amyloid polyneuropathy. A genetic mutation causes amyloid deposition in the PNS and the ANS. Treatment is liver transplantation [2].
• Hereditary sensory autonomic neuropathy (HSAN). Five distinct types of HSAN have been identified [3]. They differ in presentation and their inheritance patterns.
• Fabry disease. Fabry disease is an X-linked recessive disorder that causes and accumulation of glycolipids.

Acquired autonomic neuropathies

Primary acquired autonomic neuropathies

• Postural orthostatic tachycardia syndrome (POTS). POTS is the most common presentation of autonomic neuropathy. This is an idiopathic disorder seen in women. Patients have an orthostatic intolerance characterized by hypotension and tachycardia. In severe cases, patients may experience syncope.
• Pandysautonomia. This presentation involved diffuse involvement of both the sympathetic and parasympathetic systems.
• Idiopathic distal small-fiber neuropathy. This is a chronic distal neuropathy usually presenting with damage to sudomotor fibers (postganglionic sympathetic nerve fibers innervating the sweat glands).
• Holmes-Adie syndrome and Ross syndrome. This most likely an autoimmune disease that presents with tonic pupils or pupils with tendon areflexia.
• Chronic idiopathic anhidrosis. In this presentation, there is an idiopathic presentation with loss of sweating. Secondary acquired autonomic neuropathies (metabolic disorders)

Secondary Acquired Autonomic Neuropathies

• Diabetes mellitus (DM). Neuropathy is the most common complication of DM and may have both somatic and autonomic components [4], [5], [6], [7].
• Uremic neuropathy. Uremic neuropathy is primarily a somatic neuropathy but there may be autonomic components.
• Liver disease. Biliary cirrhosis can be associated with autonomic neuropathy in 48% of patients.
• Vitamin deficiency and nutrition-related neuropathy. Vitamin B-12 deficiency may cause an autonomic neuropathy [8].
• Toxic and drug-induced autonomic neuropathy. A number of chemotherapy drugs may cause autonomic neuropathy. Other drugs include, acrylamide, pyridoxine, thallium, amiodarone, perhexiline, and gemcitabine [9].
• Alcohol associated autonomic neuropathy. Alcohol use may have a direct effect on the autonomic nervous system or the damage may be mediated by a thiamine deficiency [10].
• Infectious diseases. A number of diseases have been associated with autonomic neuropathy: Lyme disease, HIV, Chagas disease, Botulsim, Diptheria and Leprosy
• Celiac disease. Patients with celiac disease may have autonomic neuropathies in 50% of cases.
• Sjögren syndrome. It is thought that cause of neuropathy is via autoimmune mechanism [11].
• Rheumatoid arthritis, systemic lupus erythematosis, and connective tissue disorders. These entities probably affect the ANS via an autoimmune mechanism.
• Acute intermittent porphyria and variegate porphyria. Disease may be secondary to drug exposure. During episodes, presentation may mimic Guillain-Barré syndrome
• Guillain-Barré syndrome. Antibodies are produced to gangliosides resulting in an autonomic neuropathy.
• Lambert-Eaton myasthenic syndrome. In this syndrome, antibodies are produced against presynaptic voltage-gated P/Q-type Ca2+ channels.
• Paraneoplastic autonomic neuropathy. With paraneoplastic syndrome, anti-Hu antibodies are produced in 23% of patietns resulting in autonomic neuropathy.
• Amyloid neuropathy. Amyloid neuropathy can be associated with hematologic malignancies such as multiple myeloma.
• Inflammatory bowel disease. Probably mediated by an autoimmune mechanism, IBD may have associated autonomic neuropathy involving the pupillary nerves [12].

The most common symptom of autonomic neuropathy is postural hypotension. By increasing blood volume through fluid and salt intake, the symptoms of POTS can be minimized. In addition, patients need to be careful when changing postural position. When going from supine to sitting to standing, they need to move slowly and have something nearby to hold on to. As noted above, there are a number of drugs to help with some of the other symptoms of the disease, particularly with respect to bladder, bowel, or genitourinary systems.

The nervous system is divided into the central (CNS) and peripheral nervous systems (PNS) [1]. The PNS consists of the nerves that connect the CNS to the rest of the body, including not only the muscles, but also various receptors and glands. Within the PNS there are both afferent (sensory division) and efferent nerves (motor division), bringing information to the CNS and returning commands for action. The efferent system is divided into two components. There are somatic nerves that bring information to the skeletal muscles and there are autonomic nerves that transmit commands to the smooth muscle (heart) and glands. The autonomic nervous system (ANS) has two types of nerves, sympathetic and parasympathetic nerves. The parasympathetic system regulates resting body functions. Whereas, the sympathetic system allows the body to respond to need for increased activity, associated with stress or strenuous work. With autonomic neuropathy, symptoms may go unnoticed, or they may be disabling.

Neuropathy refers to a disorder of the nervous system. The autonomic nervous system is the part of the body that controls many basic functions, such as heart rate, blood pressure, sweating, bowel, and bladder function. Thus, autonomic neuropathy may present with symptoms of low blood pressure, fast heart rate, increased or decreased sweating, and problems with bowel/bladder emptying. Autonomic neuropathy can be from a familial disorder or may be secondary to another disease. Most times it is idiopathic, meaning that we will never know the cause. A careful family history and blood tests will help in determining the underlying diagnosis.

The most common form of autonomic neuropathy is postural orthostatic tachycardia syndrome (POTS). With POTS, when you suddenly stand up, you may have a drop in blood pressure (orthostatic hypotension) and your heart may beat too quickly (tachycardia). Sometimes, this may cause dizziness or even fainting (syncope). In most cases, a cause for the POTS is never identified. Usually, the problem is mild and can be controlled by increased fluid and salt intake to increase blood volume and limit alcohol to avoid dehydration. In addition, changing posture slowly allows the body time to adjust and reduces the symptoms. People with this disorder should also take care to have something/someone to hold on to as they go from sitting to standing. After standing, you should wait for a moment before beginning to walk. In more severe cases, medications can be prescribed.

Autonomic neuropathy can also prevent with increased/decreased sweating. If this is troublesome, there are medications that will diminish symptoms. Problems with bladder/bowel emptying can be treated with drug therapy and medicines for erectile dysfunction can be used when needed.

Many times autonomic neuropathy can be a symptom of another disease. The most common cause is diabetes and it is important to bring sugars under careful control to help manage the diabetic neuropathy. Autonomic neuropathy is also associated with some cancers and with autoimmune diseases. It is important to look for these other causes.

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