International study on the psychometric attributes of the non-motor symptoms scale in Parkinson disease

BACKGROUND

Nonmotor symptoms (NMS) have a great impact on patients with Parkinson disease (PD). The Non-Motor Symptoms Scale (NMSS) is an instrument specifically designed for the comprehensive assessment of NMS in patients with PD. NMSS psychometric properties have been tested in this study.

METHODS

Data were collected in 12 centers across 10 countries in America, Asia, and Europe. In addition to the NMSS, the following measures were applied: Scales for Outcomes in Parkinson's Disease (SCOPA)-Motor, SCOPA-Psychiatric Complications (SCOPA-PC), SCOPA-Cognition, Hoehn and Yahr Staging (HY), Clinical Impression of Severity Index for Parkinson's Disease (CISI-PD), SCOPA-Autonomic, Parkinson's Disease Sleep Scale (PDSS), Parkinson's Disease Questionnaire-39 items (PDQ-39), and EuroQol-5 dimensions (EQ-5D). NMSS acceptability, reliability, validity, and precision were analyzed.

RESULTS

Four hundred eleven patients with PD, 61.3% men, were recruited. The mean age was 64.5 +/- 9.9 years, and mean disease duration was 8.1 +/- 5.7 years. The NMSS score was 57.1 +/- 44.0 points. The scale was free of floor or ceiling effects. For domains, the Cronbach alpha coefficient ranged from 0.44 to 0.85. The intraclass correlation coefficient (0.90 for the total score, 0.67-0.91 for domains) and Lin concordance coefficient (0.88) suggested satisfactory reproducibility. The NMSS total score correlated significantly with SCOPA-Autonomic, PDQ-39, and EQ-5D (r(S) = 0.57-0.70). Association was close between NMSS domains and the corresponding SCOPA-Autonomic domains (r(S) = 0.51-0.65) and also with scales measuring related constructs (PDSS, SCOPA-PC) (all p < 0.0001). The NMSS total score was higher for women (p < 0.02) and for increasing disease duration, HY, and CISI-PD severity level (p < 0.001). The SEM was 13.91 for total score and 1.71 to 4.73 for domains.

CONCLUSION

The Non-Motor Symptoms Scale is an acceptable, reproducible, valid, and precise assessment instrument for nonmotor symptoms in Parkinson disease.

Bobble-head doll syndrome: some atypical features with a new lesion and review of the literature

Bobble-head doll syndrome is a rare and unique movement disorder encountered in children. It is characterized by continuous or episodic involuntary forward and backward and side to side movement of the head at the frequency of 2-3 Hz. Neuroimaging in most of the cases reveals third ventricular tumors, suprasellar arachnoid cysts, aqueductal stenosis and other lesions in the region of the third ventricle along with communicating hydrocephalus. In most of the circumstances, the problem starts in the first decade of life and diversion of cerebrospinal fluid by shunt operation is very often accompanied by dramatic improvement. We report one case where bobbing of the head started at around 12 years of age. Additionally, there was evidence of partial left abducens nerve palsy, tremor in the outstretched hands, difficulty in finger-nose test and tandem walking, hyperreflexia and extensor plantar response. He was unconscious on two occasions and there was evidence of gross hydrocephalus along with a thin membranous web, running transversely across the lower part of the aqueduct of Sylvius without any cerebrospinal fluid flow void. Ventriculo-peritoneal shunt abolished the abnormal movements. We propose that the aqueductal web was the offending agent for the pathogenesis of bobble-head doll syndrome in our case and this lesion has not been identified in the cases reported so far. Relevant literature in this regard has also been reviewed.

Orthostatic tremor: report of a case and review of the literature

Orthostatic tremor is a rare movement disorder characterized by tremulousness of the lower limbs on standing that disappears on walking, sitting or on lying down and a distinctive electromyographic burst of 14 to 16 Hz. On inspection, fine ripples can sometimes be seen over the quadriceps on standing. The tremor has a tendency to reappear even in the supine posture if the lower limb muscles are put to an isometric contraction state, indicating thereby that in spite of the fact that the tremor occurs on standing, it is essentially 'orthostasis independent' and the central factor is the contraction of the muscles. As a matter of fact, the tremor is abolished if the subject is suspended by harness, thus relieving him of muscle contraction. Doubts are being cast whether it is a variant of essential tremor since a number of families are being reported to be suffering from this disease as well. Positron emission tomography reveals hyperactivity of cerebellum in orthostatic tremor as it shows in essential tremor, therefore lending credence to such a hypothesis. However, lack of response to alcohol, propranolol and primidone in orthostatic tremor stands out as a serious challenge to such a view. Lack of positive family history, synchrony of contracting group of muscles and negative 'resetting' of the tremor by increasing peripheral load-phenomena consistently observed in orthostatic tremor and not in essential tremor, are other features that often help to distinguish between the two conditions. We report a case of orthostatic tremor that presented with the classical clinical and electromyographic features. Relevant literature in this regard is also being reviewed.

Sporadic paroxysmal exercise induced dystonia: report of a case and review of the literature

Sporadic paroxysmal exercise induced dystonia (PEID) is a rare condition. So far only fifteen cases have been reported in the world literature. It is characterised by dystonic posture on prolonged exercise, which gets relieved with rest. In general, these are refractory to medical treatment. We report one such case, along with review of the literature. The lower limbs were spared and only right shoulder was tucked up with the head turning to right side. The duration of exercise necessary to bring out the dystonic posture gradually diminished with time, a feature not reported previously.

Profile of electrocardiographic changes in Duchenne muscular dystrophy

Cardiac changes often culminating in cardiac failure are at times a dramatic cause of death in patients of Duchenne muscular dystrophy. These changes are probably invariable in such cases though they may escape detection in early stages by clinical examination or radiological investigation. Electrocardiography serves as a sensitive, non-invasive and inexpensive tool to detect these changes. Fifty-four cases of Duchenne muscular dystrophy were studied clinically and were confirmed by biochemical and electroneuromyographic studies. They were then subjected to electrocardiographic studies. A number of electrocardiographic changes were observed, like tachycardia in 77.77%, deep Q in leads I, aVL, V6 in 53.70%, prolonged VAT in 37.03%, deep Q in leads II, III, aVF in 29.62% and prolonged Q-Tc interval in 25.92% cases. Some of these were distinctive enough to warrant attention for cases of Duchenne muscular dystrophy.