Role of Nerve Conduction Studies in Hansen's Disease.

Background and Objective: To report the role of nerve conduction study (NCS) in diagnosis, monitoring, and prognosis of Hansen's disease (HD). Materials and Methods: In a hospital-based prospecive observational study, the patients with HD as per World Health Organization (WHO) criteria were included; muscle wasting power, reflexes, and sensations were recorded. Motor NCS of median, ulnar, and peroneal nerves and sensory NCS of ulnar, median, and sural nerves were recorded. Disability was graded using WHO grading scale. The outcome was assessed after 6 months using modified Rankin scale. Results: In the present study, 38 patients with a median age of 40 (15-80) years and five females were included. The diagnosis was tuberculoid in seven, borderline tuberculoid in 23, borderline lepromatous in two, and borderline in six patients. The disability was grade 1 and 2 in 19 patients each. Out of 480 nerves studied, NCS was normal in 139 sensory (57.4%) and 160 (67.2%) motor nerves. NCSs were axonal in seven sensory and eight motor nerves, demyelinating in three nerves, and mixed in one in seven patients who had lepra reaction. NCS findings did not correlate with disability (p = 1.0) or outcome (0.304) and provided additional information in 11 nerves (seven patients). Peripheral nerves were enlarged in 79. NCSs were normal in 32 (29.90%) in thickened nerves. Conclusion: In HD, NCS abnormalities correlated with respective sensory or motor abnormality but related with neither disability nor the outcome.

Neuropathy in a cohort of restless leg syndrome patients.

This study aims to evaluate the types of neuropathy in a cohort of restless leg syndrome (RLS) patients and compare them with primary RLS. RLS symptoms can occur in peripheral neuropathy and may cause diagnostic confusion, and there is a paucity of studies comparing neuropathic RLS and primary RLS. Patients with RLS diagnosed according to the international restless legs syndrome study group criteria were categorized as primary RLS or secondary. Those with evidence of peripheral neuropathy were categorized as neuropathic RLS. The demographic, clinical, laboratory profile and therapeutic response to dopamine agonists at 6 months and 1 year of neuropathic RLS patients were compared between primary and secondary RLS patients. There were 82 patients with RLS of whom 22 had peripheral neuropathy and 28 had primary RLS. The etiology of neuropathic RLS was diabetes mellitus in 13, renal failure in six, hypothyroidism in five, demyelinating in two, nutritional deficiency in three, leprosy in one, and miscellaneous etiologies in four patients. The neuropathic RLS patients were older (46.0±14.1 versus 35.8±15.4 years), had shorter duration of illness (1.4±1.4 versus 6.2±6.2 years) and were more frequently symptomatic. RLS symptoms were asymmetric in primary RLS patients compared to neuropathic RLS (25% versus 0%). The therapeutic response was similar in both groups.

Diagnostic approach to peripheral neuropathy.

Peripheral neuropathy refers to disorders of the peripheral nervous system. They have numerous causes and diverse presentations; hence, a systematic and logical approach is needed for cost-effective diagnosis, especially of treatable neuropathies. A detailed history of symptoms, family and occupational history should be obtained. General and systemic examinations provide valuable clues. Neurological examinations investigating sensory, motor and autonomic signs help to define the topography and nature of neuropathy. Large fiber neuropathy manifests with the loss of joint position and vibration sense and sensory ataxia, whereas small fiber neuropathy manifests with the impairment of pain, temperature and autonomic functions. Electrodiagnostic (EDx) tests include sensory, motor nerve conduction, F response, H reflex and needle electromyography (EMG). EDx helps in documenting the extent of sensory motor deficits, categorizing demyelinating (prolonged terminal latency, slowing of nerve conduction velocity, dispersion and conduction block) and axonal (marginal slowing of nerve conduction and small compound muscle or sensory action potential and dennervation on EMG). Uniform demyelinating features are suggestive of hereditary demyelination, whereas difference between nerves and segments of the same nerve favor acquired demyelination. Finally, neuropathy is classified into mononeuropathy commonly due to entrapment or trauma; mononeuropathy multiplex commonly due to leprosy and vasculitis; and polyneuropathy due to systemic, metabolic or toxic etiology. Laboratory investigations are carried out as indicated and specialized tests such as biochemical, immunological, genetic studies, cerebrospinal fluid (CSF) examination and nerve biopsy are carried out in selected patients. Approximately 20% patients with neuropathy remain undiagnosed but the prognosis is not bad in them.

Pseudoathetosis in a patient with leprosy.

A 35-year-old man with borderline tuberculoid leprosy developed Type I lepra reaction 12 days after anti-leprosy treatment. There was acute worsening of neuropathic symptoms and skin lesions. He developed severe sensory ataxia and pseudoathetosis resulting in marked disability. His symptoms significantly improved on corticosteroid therapy.