sudomotor

The proposed pathomechanisms of idiopathic pure sudomotor failure include:

Sudomotor nerve.

Two quantitative tests that may be used are the resting sweat output test and the quantitative sudomotor axon reflex test.

The most common symptoms at onset are related to orthostatic intolerance, as well as gastrointestinal and sudomotor dysfunction (Suarez et al. 1994).

Quantitative sudomotor axon reflex test and microneurography are used in the diagnosis of AIGA.

The finding of abnormal quantitive sudomotor axon test results or skin biospies in this subset have been interpreted as supporting an autonomic neuropathic process.

The Minor test (starch-iodine test) described by Minor in 1928 is a qualitative test used to evaluate sudomotor function (sweating).

Abnormal distal sudomotor findings are frequently reported suggesting patchy small fiber neuropathy in a large subset of POTS patients.

Contrary to what is commonly accepted, it emerges that these causalgias were certainly major by the importance of the vasomotor and sudomotor symptoms, but stemmed from minor neurological lesions.

Sympathetic denervation has also been assessed by investigating sweating ability in patients with unexplained gut dysmotility using the thermoregulatory sweat test and quantitative sudomotor axon reflex test.

The term IPSF represent a distinct subgroup of AIGA without sudomotor neuropathy or sweat gland failure.

The intradermal injection of acetylcholine is effective in stimulating sweat glands because acetylcholine, and not noradrenaline, is the post ganglionic sympathetic neurotransmitter in sudomotor fibres.

Sudomotor innervation is the cholinergic innervation of the sympathetic nervous system prominent in sweat glands which causes perspiration to occur via activation of muscarinic acetylcholine receptors.

The loss of sudomotor function seen in constipated patients in this study would at first indicate a degree of impairment of the sympathetic nervous system which would result in the loss of inhibitory tone on gut smooth muscle.

Common symptoms of neurapraxia are disturbances in sensation, weakness of muscle, vasomotor and sudomotor paralysis in the region of the affected nerve or nerves, and abnormal sensitivity of the nerve at the point of injury.

Camilleri and Fealey, recently using the thermoregulatory test and a quantitative sudomotor axon reflex test, showed in eight patients with gastrointestinal proglems that an idiopathic autonomic denervation may be an aertiological factor in non-organic intestinal dysmotility.

AIGA is classified into 3 subgroups: idiopathic pure sudomotor failure (IPSF), sweat gland failure (SGF), and sudomotor neuropathy, with each subgroup presenting a different pathogenesis.

Idiopathic pure sudomotor failure (IPSF) is the most common cause of a rare disorder known as acquired idiopathic generalized anhidrosis (AIGA), a clinical syndrome characterized by generalized decrease or absence of sweating without other autonomic and somatic nervous dysfunctions and without persistent organic cutaneous lesions.