Spectrum of Movement Disorders in Niemann-Pick Disease Type C.

Introduction: Niemann-Pick disease type C (NPC) is an autosomal recessive neurovisceral lipid storage disorder caused by mutations in the NPC 1 or 2 genes. Movement disorders can occur as the first symptom and as predominant symptom mainly in juvenile-onset. The frequency and heterogeneity of movement disorders in NPC are not well described. We studied the frequency and spectrum of movement disorders in patients with NPC of different age of onset. Methods: Retrospective chart review of patients with NPC diagnosed based on the Suspicion Index tool and demonstration of foamy macrophages/sea-blue histiocytes in bone marrow aspirate. Results: We report 9 cases of NPC with 2 patients of late-infantile, 4 juvenile-onset and 3 of adult-onset. The mean age at onset of symptoms was 11.7 ± 10.4 (range 4-38 years) and the median duration of illness was 4 years. Vertical supranuclear gaze palsy (VSGP) was noted in 8 patients and VSGP with slowing of saccade in 1 patient. Splenomegaly was seen in 5 patients. Movement disorders as the first symptom occurred in 4 patients. Dystonia was the first symptom in 2 patients and cerebellar ataxia in 2 patients. Cerebellar ataxia occurred during the course of illness in 5 patients, dystonia in 6 patients. One patient with late-infantile NPC had stimulus-sensitive myoclonus. Conclusion: Movement disorders are common in NPC and occur as a presenting symptom. Cerebellar ataxia and dystonia are the most common movement disorder in NPC. Vertical supranuclear gaze palsy along with the movement disorders should lead to clinical suspicion of NPC.

Cross-Sectional Area Reference Values of Nerves in the Upper and Lower Extremities using Ultrasonography in the Indian Population.

Background and Purpose: Cross-sectional area (CSA) is the most important parameter to study peripheral nerves by high-resolution ultrasonography. The aim was to acquire normative data of CSA of the main upper and lower limb nerves in the Indian population. Methods: CSA of nerves was determined in 100 healthy volunteers at 11 predetermined sites: median and ulnar at the wrist, mid-forearm, elbow; radial (spiral groove); tibial (popliteal fossa, medial malleolus); common peroneal (CPN, fibular head) and sural (lateral malleolus). Results: The mean age of participants was 40.7 ± 13.0 years (range: 18-79). Fifty were < 40 years of age. The mean height, weight and BMI were 161.5 ± 8.3 centimeters (range: 145-179), 58.6 ± 10.1 kilograms (range: 32-90) and 22.4 ± 3.2 kilogram/square meter (range: 14.03-30.44), respectively. The median and ulnar nerve measurements were non-uniform throughout its course, and the CSA was largest at the elbow and ulnar groove, respectively. With advancing age, there was a significant difference for median and ulnar nerves at the wrist (median P = 0.002, ulnar P = 0.009) and tibial nerve (popliteal fossa, P = 0.045, medial malleolus, P = 0.005), CPN (P = 0.047). Men had greater CSA of upper limb nerves and tibial nerves at popliteal fossa (P < 0.05) as compared to women. A positive correlation was noted with weight. Conclusion: It is apt for every defined population to have its own set of normative data of CSA as it varies with ethnicity, age, and the built of individuals. We provide a valuable set of CSA data for nerves in the Indian population, which can be used for comparison while investigating peripheral nerve disorders.