Understanding of Huntington’s disease (HD) has been evolving since its early descriptions from nineteenth century. Significant breakthroughs into HD pathophysiology and therapeutic targets have been seen in last 50 years. Most of the publications in relation to HD are from European and American continents, indicating geographical higher prevalence. HD in India has been reported since early 1950s in the form of case reports and series, with exception of varying references in ancient Indian literature as “Tandavaroga.” In this review, we have amalgamated the various Indian publications on HD till date.

Ocular manifestations form an important clinical component of several movement disorders. Both hypokinetic and hyperkinetic movement disorders can involve the eye. Ophthalmological manifestations can arise due to dysfunction at the level of retina, optic nerves, oculomotor system, or subcortical or visual cortex. Ophthalmological findings help in differentiating various movement disorders and give a clue about their severity. These follow or may precede the diagnosis of movement disorders. Basal ganglia and its various nuclei especially substantia nigra pars reticulata play an important role in the genesis of eye movements through its connections with the superior colliculus. Eye movement abnormalities using quantitative recording techniques are now being considered as noninvasive biomarkers not only for the diagnosis but also to track the progression of disease as well as to study the effects of therapies in various movement disorders. Moreover, there is ample evidence of presence of retinal degeneration in various neurodegenerative diseases evaluated using optical coherence tomography. Various patterns of retinal thinning have been described in different movement disorders and have been found to have a correlation with the stage and severity of the disorder. In this review, we discuss ophthalmological findings of common hypokinetic and hyperkinetic movement disorders.

INTRODUCTION: Numerous studies in Huntington’s disease (HD) have shown striatum as the major site of neuronal loss, but recently the presence of neurodegeneration in other regions of the brain is gaining attention. In our study, we used voxel-based morphometry and diffusion tensor imaging to identify other areas in the brain that are involved in the disease. METHODS: The present study is a prospective study conducted in the Departments of Neurology, Psychiatry, and Neuroimaging and Interventional Radiology (NIIR), NIMHANS, Bengaluru. The study included 20 genetically confirmed HD patients and 20 healthy controls. Magnetic resonance imaging was performed on a 3-Tesla Philips Achieva scanner with a 32-channel head coil with the acquisition of whole-brain T1-weighted and DTI. RESULTS: The patients (41.25 ± 10.04 years) and controls (38.27 ± 11.29 years) were age-matched (P = 0.38), and the mean age at the onset of the symptoms of the disease was 37.53 ± 10.11 years, and the expanded CAG repeat allele was 45.95 ± 7.27 (range 40–73) repeats. All patients had psychiatric symptoms at presentation such as anger outbursts, irritability, abusive behavior, apathy, low mood, crying spells, delusions, lack of initiation, and obsessive–compulsive disorder. Compared with controls, HD patients had significant atrophy of bilateral caudate nuclei, right globus pallidus, left culmen, right precuneus, hypothalamus, and right superior temporal gyrus. Fractional anisotropy was increased in bilateral cerebral white matter and thalamus with the reduction in mean diffusivity. CONCLUSIONS: In addition to atrophy of caudate, atrophy was also observed in globus pallidus, thalamus, hypothalamus and right superior temporal gyrus. This may explain the neuropsychiatric and cognitive symptoms observed in these patients.

BACKGROUND: Sleep disorders lead to cognitive deficits in healthy people and are thought to have significant impact on cognition in Parkinson’s disease (PD). OBJECTIVE: To study the sleep pattern and its relationship to cognitive functioning in non-demented PD cohort. MATERIALS AND METHODS: Sleep was evaluated by Pittsburg Sleep Quality Index (PSQI) in a cohort of PD patients. Comprehensive assessment of cognitive domains including attention, executive functions, short/long-term verbal memory, visual memory, and visuospatial functioning was done by battery of neuro-physiological tests on patients in “ON” state. Based on the component PSQI sleep score, patients were grouped as having "good quality sleep" (PSQI score ≤ 5) or "poor quality sleep" (PSQI score > 5). The demographic profile, disease characteristics, treatment, and cognitive tests were then compared between the two groups. RESULTS: Of 130 patients with diagnosis of PD, 85 patients were included. 63 (74.1%) had good sleep quality while 22 (25.9%) had poor sleep quality. Mean age and disease characteristic were comparable between two groups except that females had statistically significant (P = 0.001) poor sleep quality as compared to men. Poor sleep quality had significant effect on cognitive functions including generativity, inhibition, set-shifting, perseveration, and attention but there was no impact of sleep on verbal memory, visual memory, and visuospatial abilities. CONCLUSION: PD patients with poor sleep quality on PSQI questionnaire should be carefully screened for presence of any cognitive impairment especially executive impairment, as these two may be inter-related. Intervention to improve sleep would have far reaching benefits to improve the quality of life of PD patients.

Oculopalatal tremor (OPT) is a unique clinical sign characterized by involuntary movements of the soft palate in synchrony with ocular nystagmus, usually the pendular type. It is highly suggestive of and is a delayed complication of a brainstem lesion, often a stroke. The mechanism and clinical implications of OPT are still not fully elucidated and present a treatable complication of brainstem disease. We searched PubMed and Google Scholar for articles with keywords “Oculopalatal tremor.” Most relevant articles were reviewed, based on the number of citations and information was collated by both the authors. We present two cases of OPT which illustrate the clinical spectrum of OPT.

Acute to subacute onset chorea is commonly due to stroke, metabolic, post-infectious, and autoimmune disorders. Chorea in diabetes (DM) patient is mostly due to hyperglycemia, and few cases were reported due to hypoglycemia. The mechanism at the cellular level is still evolving. The MRI changes in diabetic chorea patients are variably reported. It is important to discuss our patient with hypoglycemic hemichorea because of unique features like low BMI, recently diagnosed DM on sulphonylurea with a history of hypoglycemic episodes, and acute left hemichorea that was controlled with neuroleptics, and her MRI brain showed reversible lentiform nucleus T1 hyperintensity without diffusion restriction and blooming on SWI.

Glutaric aciduria type 1 is an autosomal recessive disorder caused by mutations in GCDH gene on chromosome 19 leading to the deficiency of glutaryl-CoA dehydrogenase which causes an abnormal metabolism of lysine, hydroxylysine and tryptophan with resultant accumulation of glutaric acid and 3-hydroxy glutaric acid. Usual presentations include macrocephaly with recurrent dystonic episodes, along with developmental regression. The diagnosis is based on characteristic magnetic resonance imaging finding of widening of sylvian fissures and urinary tandem mass spectroscopic analysis of excess glutarylcarnitine and hydroxyglutaric acid. Management includes lysine-free diet and carnitine supplementation.