Subacute Neuropathy Research Articles

Peripheral neuropathy associated with eosinophilia‐myalgia syndrome

In 1989, the Centers for Disease Control recognized the existence of an epidemic illness characterized by myalgia and eosinophilia in individuals taking preparations containing L-tryptophan. We evaluated 3 patients with eosinophilia-myalgia syndrome who presented with subacute progressive neuropathies. The neuropathies were predominantly motor and maximal in the lower extremities. Two patients were confined to a wheelchair and one was ventilator-dependent and bedridden. Sensory loss predominantly involved small fiber modalities. Electrophysiological studies showed multifocal marked conduction slowing and conduction block indicating segmental demyelination, with associated axonal degeneration that was accentuated distally. Examination of sural nerve biopsy specimens demonstrated axonal degeneration in all 3 patients and perivascular infiltrates in 2. Levels of quinolinic acid, a neurotoxic metabolite of L-tryptophan, were elevated in the cerebrospinal fluid in the 2 patients in whom it was measured. The cause of the neuropathy is unknown but may include immune mechanisms or toxicity of eosinophils, L-tryptophan, its metabolic products, or contaminants within L-tryptophan preparations.

Porphyric neuropathy and hereditary δ-aminolevulinic acid dehydratase deficiency in an adult

A man without a history of porphyric attacks developed a subacute motor neuropathy at the age of 63. At the same time the first signs of a myeloproliferative disorder were found. He had a homozygous deficiency of erythrocyte δ-aminolevulinic acid dehydratase (ALA-D) with autosomal recessive inheritance. Treatment with parenteral glucose and with hematin had a beneficial influence on the plasma ALA levels. The finding of a motor neuropathy with increased plasma levels of ALA but not of porphobilinogen (PBG) supports the potential role of ALA in the pathogenesis of porphyric neuropathy.

Disorders of the autonomic nervous system: Part 1. Pathophysiology and clinical features.

Autonomic dysfunction may result from diseases that affect primarily either the central nervous system or the peripheral autonomic nervous system. The most common pathogenesis of disturbed autonomic function in central nervous system diseases is degeneration of the intermediolateral cell columns (progressive autonomic failure) or disease or damage to descending pathways that synapse on the intermediolateral column cells (spinal cord lesions, cerebrovascular disease, brainstem tumors, multiple sclerosis). The peripheral autonomic nervous system may be damaged in isolation in the acute and subacute autonomic neuropathies or in association with a generalized peripheral neuropathy. The peripheral neuropathies most likely to cause severe autonomic disturbance are those in which small myelinated and unmyelinated fibers are damaged in the baroreflex afferents, the vagal efferents to the heart, and the sympathetic efferent pathways to the mesenteric vascular bed. Acute demyelination of the sympathetic and parasympathetic nerves in the Guillain-Barré syndrome may also cause acute autonomic dysfunction. Although autonomic disturbances may occur in other types of peripheral neuropathy, they are rarely clinically important.

Peripheral neuropathy in systemic vasculitis: clinical and electrophysiologic study of 22 patients.

Twenty-two patients with evidence of systemic vasculitis and peripheral neuropathy were clinically and electrophysiologically investigated in a retrospective study. Ten had a polyarteritis nodosa, 6 a probable polyarteritis nodosa, and 6 a Churg-Strauss syndrome. Nine patients presented clinically with mononeuropathy or mononeuropathy multiplex considered typical of ischemic involvement of peripheral nerve; nine had more diffuse neuropathy, two of them a symmetric polyneuropathy. EMG examination revealed more diffuse neuropathy than clinically predicted. Findings were of acute or subacute axonal neuropathy.

Subacute demyelinating polyneuropathy responding to corticosteroid treatment.

Ten patients with subacute demyelinating neuropathy responded satisfactorily to corticosteroid treatment. The most prominent features in these cases were (1) subacute progression of diffuse polyneuropathy over weeks and months, (2) high spinal fluid protein level, (3) marked nerve conduction abnormalities, and (4) high rate of relapse. The sural nerve biopsy specimen showed "demyelinating neuropathy." This subacute demyelination neuropathy appears to be a distinct and clinically identifiable entity in which corticosteroid treatment is indicated.

Acute and Subacute Neuropathies

Acute and Subacute Neuropathies