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Biomedical subjects

K P Bhatia

Publications and source records attributed to K P Bhatia.

At least 19 recordsLinked to original sources

Phenotypic homogeneity of the Huntington disease-like presentation in a SCA17 family.

We describe clinical and genetic analysis of a family with spinocerebellar ataxia 17 (SCA17) presenting with a Huntington disease-like (HDL) syndrome. Clinically diagnosed, HD is genetically heterogeneous. Differential diagnosis includes SCA17. However, SCA17 HDL presentation has been observed only sporadically or in solitary individuals within a family. HDL phenotypic homogeneity in SCA17 has not been described. SCA17 can present with a HDL syndrome in multiple family members.

Adult↗

Severe tongue protrusion dystonia: clinical syndromes and possible treatment.

We describe intermittent or sustained severe involuntary tongue protrusion in patients with a dystonic syndrome. Speech, swallowing, and breathing difficulties can be severe enough to be life threatening. Causes include neuroacanthocytosis, pantothenate kinase-associated neurodegeneration, Lesch-Nyhan syndrome, and postanoxic and tardive dystonia. The pathophysiology of intermittent severe tongue protrusion remains unknown. Tongue protrusion dystonia is often unresponsive to oral drugs but may benefit from botulinum toxin injections into the genioglossus muscle. Bilateral deep brain pallidal stimulation was beneficial in two cases.

Adolescent↗

Changes in forearm reciprocal inhibition following pallidal stimulation for dystonia.

The authors recorded forearm H reflex reciprocal inhibition and clinical outcome in eight patients with primary torsion dystonia before and 1, 3, and 6 months after pallidal deep brain stimulation (DBS). There was progressive increase in reciprocal inhibition after surgery, which correlated with clinical improvement. The authors conclude that pallidal DBS for dystonia results in functional reorganization of the nervous system, which includes a long-term increase in spinal inhibition.

Adult↗

Motor system inhibition in dopa-responsive dystonia and its modulation by treatment.

Dopa-responsive dystonia (DRD) causes dystonia-parkinsonism, which is abolished by levodopa. The authors assessed short intracortical inhibition and facilitation, silent period, blink reflex recovery cycle, and reciprocal inhibition in seven patients with DRD on and off treatment. Short intracortical inhibition and blink reflex recovery cycle were reduced, but increased with treatment. Silent period was normal on and off treatment. Third phase of reciprocal inhibition was reduced on and off treatment. A discrete pattern of motor inhibitory dysfunction occurs in DRD.

Blinking↗

Familial dopa-responsive cervical dystonia.

The authors present four cases from two unrelated families with young-onset predominant cervical dystonia with a dramatic sustained response to levodopa. Onset age was 12 years (range 9 to 15). Additional symptoms included postural hand tremor and laryngeal dystonia. Genetic testing for GTP cyclohydrolase I, tyrosine hydroxylase, and sepiapterin reductase was negative. These cases may represent new forms of dopa-responsive dystonia. Levodopa is advisable in all patients with young-onset cervical dystonia.

Adolescent↗

A systematic review on the diagnosis and treatment of primary (idiopathic) dystonia and dystonia plus syndromes: report of an EFNS/MDS-ES Task Force.

To review the literature on primary dystonia and dystonia plus and to provide evidence-based recommendations. Primary dystonia and dystonia plus are chronic and often disabling conditions with a widespread spectrum mainly in young people. Computerized MEDLINE and EMBASE literature reviews (1966-1967 February 2005) were conducted. The Cochrane Library was searched for relevant citations. Diagnosis and classification of dystonia are highly relevant for providing appropriate management and prognostic information, and genetic counselling. Expert observation is suggested. DYT-1 gene testing in conjunction with genetic counselling is recommended for patients with primary dystonia with onset before age 30 years and in those with an affected relative with early onset. Positive genetic testing for dystonia (e.g. DYT-1) is not sufficient to make diagnosis of dystonia. Individuals with myoclonus should be tested for the epsilon-sarcoglycan gene (DYT-11). A levodopa trial is warranted in every patient with early onset dystonia without an alternative diagnosis. Brain imaging is not routinely required when there is a confident diagnosis of primary dystonia in adult patients, whereas it is necessary in the paediatric population. Botulinum toxin (BoNT) type A (or type B if there is resistance to type A) can be regarded as first line treatment for primary cranial (excluding oromandibular) or cervical dystonia and can be effective in writing dystonia. Actual evidence is lacking on direct comparison of the clinical efficacy and safety of BoNT-A vs. BoNT-B. Pallidal deep brain stimulation (DBS) is considered a good option, particularly for generalized or cervical dystonia, after medication or BoNT have failed to provide adequate improvement. Selective peripheral denervation is a safe procedure that is indicated exclusively in cervical dystonia. Intrathecal baclofen can be indicated in patients where secondary dystonia is combined with spasticity. The absolute and comparative efficacy and tolerability of drugs in dystonia, including anticholinergic and antidopaminergic drugs, is poorly documented and no evidence-based recommendations can be made to guide prescribing.

Botulinum Toxins↗

Late-onset episodic ataxia type 2 due to an in-frame insertion in CACNA1A.

Episodic ataxia type 2 (EA2) is caused by calcium channel (CACNA1A) mutations and typically begins before age 20 years. The molecular basis of late-onset EA2 is unclear. The authors describe a case of late-onset EA2 associated with the first multiple-base pair insertion in CACNA1A. Molecular expression revealed evidence of impaired calcium channel function, suggesting that genetically induced reduction in calcium channel function may associate with cases of late-onset EA2.

Adult↗

Young onset limb spasticity with PSP-like brain and spinal cord NFT-tau pathology.

A 30-year-old white man presented with a sporadic form of gradually progressive spastic gait and, later, supranuclear vertical and horizontal gaze palsy, mild cognitive impairment, loss of postural reflexes, and falls. DNA analysis revealed H1/H1 haplotype without tau gene (exons 9 to 13) mutation. Eight years later, postmortem revealed a tauopathy similar to progressive supranuclear palsy. Unusual aspects were early age at onset, neurofibrillary tangle, and tau involvement of the cord.

Adult↗

The epsilon-sarcoglycan gene in myoclonic syndromes.

Mutations in the epsilon-sarcoglycan gene (SGCE) are associated with familial myoclonus dystonia, but the full spectrum of the phenotype may not be fully defined. We screened 58 individuals with a range of myoclonic/dystonic syndromes for SGCE mutations. We found mutations (three of them novel) in six (21%) of the 29 patients with essential myoclonus and myoclonic dystonia, but did not find mutations in the 29 patients with other phenotypes.

Age of Onset↗

Dopaminergic dysfunction in unrelated, asymptomatic carriers of a single parkin mutation.

Parkin disease is usually autosomal recessive; however, two studies have shown that asymptomatic heterozygotes have nigrostriatal dysfunction and even manifest subtle extrapyramidal signs. The authors used 18F-dopa PET to study 13 asymptomatic parkin heterozygotes and found a significant reduction of (18)F-dopa uptake in caudate, putamen, ventral, and dorsal midbrain compared with control subjects. Four had subtle extrapyramidal signs. Parkin heterozygosity is a risk factor for nigrostriatal dysfunction and in some may contribute to late-onset Parkinson disease.

Aged↗

Tracing Sydenham's chorea: historical documents from a British paediatric hospital.

Sydenham's chorea (SC) became a well defined nosological entity only during the second half of the nineteenth century. Such progress was promoted by the availability of large clinical series provided by newly founded paediatric hospitals. This paper analyses the demographic and clinical features of patients with chorea admitted to the first British paediatric hospital (the Hospital for Sick Children, Great Ormond Street, London) between 1852 and 1936. The seasonal and demographic characteristics of SC during this time appear strikingly similar to those observed today, and witness the introduction of modern "statistically averaging" techniques in the approach to complex paediatric syndromes. Great Ormond Street (GOS) hospital case notes provide detailed descriptions of the "typical cases" of SC, and show that British physicians working in the early age of paediatric hospitals succeeded in recognising the most distinctive clinical features of this fascinating condition.

Child↗

Parkinsonism following bilateral lesions of the globus pallidus: performance on a variety of motor tasks shows similarities with Parkinson's disease.

OBJECTIVES: The authors report the results of detailed investigations into the motor function of a patient who, after a heavy drinking binge and subsequent unconsciousness, respiratory acidosis, and initial recovery, developed parkinsonism characterised by hypophonic speech and palilalia, "fast micrographia", impaired postural reflexes, and brady/akinesia in proximal (but not distal) alternating upper limb movements. METHODS: In addition to brain magnetic resonance imaging (MRI), different aspects of motor function were investigated using reaction time (RT) tasks, pegboard and finger tapping tasks, flex and squeeze tasks, movement related cortical potentials (MRCPs), and contingent negative variation (CNV). Cognitive function was also assessed. The results were compared to those previously reported in patients with Parkinson's disease (PD). RESULTS: Brain MRI showed isolated and bilateral globus pallidus (GP) lesions covering mainly the external parts (GPe). These lesions were most probably secondary to respiratory acidosis, as other investigations failed to reveal an alternative cause. The results of the RT tasks showed that the patient had difficulties in preparing and maintaining preparation for a forthcoming movement. MRCP and CNV studies were in line with this, as the early component of the MRCP and CNV were absent prior to movement. The patient's performance on pegboard and finger tapping, and flex and squeeze tasks was normal when performed with one hand, but clearly deteriorated when using both hands simultaneously or sequentially. CONCLUSIONS: In general, the present results were similar to those reported previously in patients with PD. This provides further indirect evidence that the output of globus pallidus is of major importance in abnormal motor function in PD. The possible similarities of the functional status of GP in PD and our case are discussed.

Acidosis, Respiratory↗

Capturing the true burden of dystonia on patients: the Cervical Dystonia Impact Profile (CDIP-58).

OBJECTIVES: To develop a new rating scale for measuring the health impact of cervical dystonia (CD) that includes patients' perceptions and complements existing observer dependent clinician rating scales. METHODS: Scale development was in three stages. In Stage 1, a large pool of items was generated from patient interviews (n = 25), expert opinion, and literature review. In Stage 2, these items were administered by postal survey to people with CD. The resulting data were analyzed using Rasch item analysis to construct, from the item pool, a rating scale that satisfied criteria for rigorous measurement. In Stage 3, the measurement properties of this rating scale were examined in an independent sample of people with CD. RESULTS: In Stage 1, 150 items concerning the health impact of CD were generated. In Stage 2, 556 people completed questionnaires (87% response rate) and a 58-item rating scale measuring the health impact of CD in eight areas was constructed (CD Impact Profile, CDIP-58). In Stage 3, CDIP-58 data from 391 people (87% response rate) were received. Analyses supported the measurement of eight unidimensional constructs (infit mean square range 0.62 to 1.50), item calibration (33.37 to 67.56), and patient separation statistics (2.59 to 3.38). Items demonstrated stable calibrations in subgroups of people with CD supporting the stability of the CDIP-58. CONCLUSIONS: The CDIP-58 is a reliable and valid patient-based rating scale measuring the health impact of CD in eight health dimensions.

Adult↗

Anti-basal ganglia antibodies in patients with atypical dystonia and tics: a prospective study.

Anti-basal ganglia antibodies (ABGA) are associated with movement disorders in children, but have not been assessed in adult onset movement disorders. In a prospective assessment ABGA were positive in 65% of a group of 65 patients with atypical movement disorders, but were very rare in healthy adults and adults with idiopathic dystonia. An autoimmune mechanism may underlie a proportion of cases of atypical movement disorders.

Adolescent↗

Olfaction differentiates parkin disease from early-onset parkinsonism and Parkinson disease.

The authors studied whether olfactory dysfunction is present in parkin disease using the University of Pennsylvania Smell Identification Test (UPSIT). The mean UPSIT score in parkin patients was 27.3 (95% CI 24.4 to 30.2). This did not differ from the normal group mean of 29.4 (95% CI 28.0 to 30.7; p = 0.22) but was higher than the Parkinson disease group (mean 14.3; 95% CI 12.2 to 19.5; p < 0.0001) and the parkin-negative group (mean 17.1; 95% CI 14.8 to 16.3; p < 0.0001) values. Parkin disease may be a distinct and separate entity from Parkinson disease.

Age of Onset↗

Patterns of EMG-EMG coherence in limb dystonia.

Dystonia of the limbs may be due to a wide range of aetiologies and may cause major functional limitation. We investigated whether the previously described pathological 4 to 7 Hz drive to muscles in cervical dystonia is present in patients with aetiologically different types of dystonia of the upper and lower limbs. To this end, we studied 12 symptomatic and 4 asymptomatic carriers of the DYT1 gene, 6 patients with symptomatic dystonia due to focal basal ganglia lesions, and 11 patients with fixed dystonia, a condition assumed to be mostly psychogenic in aetiology. We evaluated EMG-EMG coherence in the tibialis anterior (TA) of these and 15 healthy control subjects. Ten of 12 (83%) of symptomatic DYT1 patients had an excessive 4 to 7 Hz common drive to TA, evident as an inflated coherence in this band. This drive also involved the gastrocnemius, leading to co-contracting electromyographic bursts. In contrast, asymptomatic DYT1 carriers, patients with symptomatic dystonia, patients with fixed dystonia, and healthy subjects showed no evidence of such a drive or any other distinguishing electrophysiological feature. Moreover, the pathological 4 to 7 Hz drive in symptomatic DYT1 patients was much less common in the upper limb, where it was only present in 2 of 6 (33%) patients with clinical involvement of the arms. We conclude that the nature of the abnormal drive to dystonic muscles may vary according to the muscles under consideration and, particularly, with aetiology.

Adult↗