Neurological examination quiz Part 3

The positive likelihood ratios for Parkinson’s disease are: shuffling, freezing and festinating gait – 8; rigidity and bradykinesia – 4.5; positive glabellar tap – 4.5; micrographia – 4.2; difficulty walking heel-to-toe – 2.9;  generalised increase in tone – 1.5; resting tremor – 1.4;. (link)

The negative likelihood ratios for Parkinson’s disease are: generalised increase in tone – 0.8; resting tremor – 0.5; rigidity and bradykinesia – 0.12; shuffling, freezing and festinating gait – 0.4; difficulty walking heel-to-toe – 0.32;  positive glabellar tap – 0.13; micrographia – 0.35. (link)

Acute dystonia typically has slow, irregular continuous, spasm like muscular contractions that result in slow movements or abnormal postures with contractions that continue for > 2 sec. (link)

Akathisia is usually characterised by motor restlessness with increased frequency of regular movements, especially in the legs. (link)

Dyskinesia typically has rapid, irregular, repetitive contractions with motionless intervals between contractions and increased movements during activity and by anxiety. (link)

Chorea typically has continuous, randomly distributed movements that are irregular in timing and quality and seem to flow from one part of the body to another with no pattern. (link)

Hemiballismus typically has large amplitude movements predominantly involving proximal muscles that are irregular in timing and quality. (link)

Tics are repetitive, irregular, stereotyped movements or vocalisations that are usually able to be consciously suppressed and are most pronounced when relaxed. (link)

Tremor typically has rhythmical continuous pendular movements of  variable amplitude, but fixed frequency with no movement free intervals. (link)

Physiological tremor is the only high frequency tremor of the choices given. It is postural and only affects the arms. Parkinsonian tremor is a low frequency tremor that affects the arms to a greater extent than the legs and face. Cerebellar tremor is also low frequency and affects the arms and trunk, more than the legs. Essential tremor is a low frequency tremor that affects the arms more than the head and legs. Neuropathic tremor is also low frequency and difficult to differentiate from essential tremor. (link)

Parkinsonian tremor is the only one of the choices that is present at rest. (link)

Patients with receptive dysphasia are unable to understand written and spoken language. (link)

Conductive dysphasia is due to lesions of the arcuate fasciculus of the temporal lobe. (link)

Hallucinations or delusions are more common in dementia with Lewy bodies. (link)

The MMSE score is usually < 24. Scores of 24-28 indicate early cognitive impairment. The criteria for the diagnosis of dementia include cognitive loss in two or more domains (memory, language, calculations, orientation, judgment), with the loss must be of sufficient severity to cause disability and a MMSE < 24. (link)