Clonic perseveration following thalamofrontal disconnection: a distinctive movement disorder.

We describe four patients who developed asymmetrical, rhythmic, stereotyped, and repetitive movements of the upper and lower limbs hours to days after infarction that involved the thalamus and/or basal ganglia. The movements appeared to occur spontaneously and were initially labeled as focal motor seizures, ballism, or tremor; they could however, be induced by passive movement of the limbs. The movements most commonly observed were scratching or rubbing movements of the hands that were of such persistence as to cause trauma to the skin; in the lower limbs, the heel was run up and down the bed sheet, often until it bled. The movements were part of a syndrome characterised initially by a reduced level of consciousness and followed by aspontaneity, usually with mutism and frontal release signs. One patient who had relatively preserved cognition and language repeated words or phrases again and again when encouraged to speak, but had no difficulty changing responses appropriately to different cues. In drawing, he overwrote each figure but could change the figure on command. The distinctive movement disorder in these patients was due to clonic perseveration. We suggest that clonic perseveration results from disconnection of prefrontal cortico-basal ganglia-thalamo-cortical loops that are important for the termination of motor plans. Clonic perseveration should be recognised as a movement disorder following thalamic lesions.

Diffuse Lewy body disease: clinical features in nine cases without coexistent Alzheimer's disease.

OBJECTIVE: To further elucidate the relation between diffuse Lewy body disease and Parkinson's disease. METHODS AND RESULTS: The clinical features of nine cases of pure diffuse Lewy body disease without pathological evidence of coexisting Alzheimer's neuritic pathology were reported. All patients were aged less than 70 years at onset (mean 62 years). Five patients presented with clinical features, which included assymetric resting tremor had levodopa responsiveness, which were initially indistinguishable from idiopathic Parkinson's disease. All five patients later became demented (mean of three years after presentation). Two further patients presented with parkinsonism and dementia and two patients presented with dementia and developed parkinsonism at a later stage. Hallucinations appeared 2.5-9 years after the onset of symptoms in six patients and were a presenting feature in one patient. All patients met the pathological criteria of idiopathic Parkinson's disease, with respect to the midbrain changes, in addition to having diffuse cortical Lewy bodies. CONCLUSIONS: Diffuse Lewy body disease may present a parkinsonism, dementia, or both depending on whether the Lewy body pathology begins in the midbrain, the cortex, or both together. When it begins in the midbrain, diffuse Lewy body disease is indistinguishable initially from idiopathic Parkinson's disease. Diffuse Lewy body disease may be a common cause of dementia complicating Parkinson's disease.

Recumbent tic.

A 59-year-old man with a 30-year history of an unusual movement disorder characterised by involuntary axial spasms that occur only in recumbency is described. Clinical and electrophysiological evidence suggest that this disorder is best characterised as a simple tic of unusual form. We have coined the term "recumbent tic" to describe this disorder.

Spinal cord compression in prostate cancer. A 10-year experience.

Of 478 patients treated at a single institution for prostate cancer, 29 developed spinal cord or cauda equina compression. In 5 patients, spinal cord compression was the first evidence of malignancy. Clinical features were predominantly pain, weakness, sensory and sphincter disturbance. The median duration of symptoms was 2 weeks, although the diagnosis was made rapidly at presentation. Clinical diagnosis correlated well with myelographic findings. Only 1 patient suffered neurological deterioration as a consequence of myelography. The functional outcome was dependent on the ability to walk prior to treatment. The median survival in those who were bedridden following treatment was 6 weeks (range 3.5-13) and 21 weeks (range 7-110+) in those who were ambulant following therapy.

Familial motor neuron disease: differing penetrance in large pedigrees.

It is likely that adult-onset motor neuron disease is inherited more frequently than has previously been believed. We have studied 9 families with familial motor neuron disease and have found apparently wide variation in penetrance. Only one has autosomal dominant inheritance with high penetrance and in this family the average age of onset is similar to that reported in reviews of familial motor neuron disease. The remaining families have a pattern consistent with autosomal dominant inheritance with diminished penetrance. The average ages of onset in these families are comparable with those in sporadic motor neuron disease. Low penetrance appears to be related to higher average age of disease onset because gene carriers have an increased likelihood of dying from other causes before developing motor neuron disease. When penetrance is low the family history may be unknown, causing affected individuals to be mistakenly regarded as having sporadic disease. We conclude that the incidence of familial motor neuron disease is likely to have been underestimated by the exclusion of apparently sporadic cases in which the familial disease has low penetrance. These results and conclusions imply that the lower average age of disease onset reported in familial motor neuron disease may be due to selective recognition of high penetrance families with lower average ages of onset.

Clonic perseveration.

Two patients are described in whom clonic perseveration was observed following infarction of the midbrain and thalamus. In one patient perseveration was confined to movements of one side of the body and was associated with a grasp reflex on the same side. In the other patient perseveration occurred in movements of both sides of the body and involved drawing, writing and speech. It was possible to induce clonic perseveration in both patients by passive limb movements, a feature of this condition which has not been described previously. Evidence is presented that this type of perseveration is, to some extent, under voluntary control. It is suggested that the role of psychological factors in perseveration has been underestimated in the past.

Temper tantrums, epilepsy and episodic dyscontrol.

Seventeen patients were seen by a neurologist for diagnosis of temper tantrums. The referring psychiatrist had thought that they might have been caused by organic disease, either epilepsy or the episodic dyscontrol syndrome. The final diagnosis in every case was temper tantrums due to psychological causes. The patients had a wide range of psychiatric disorders. Theories that might explain the tantrums are discussed.

The nasotemporal division of retina in the Siamese cat.

By sectioning one optic tract in Siamese kittens and allowing sufficient time for the affected ganglion cells to degenerate and disappear, we have obtained maps of the distribution of ipsi- and contralaterally projecting ganglion cells in the retina of the Siamese cat. As previous work predicted, many ganglion cells in the Siamese cat retina project contralaterally which, in the normally pigmented cat, would project ipsilaterally. The transition from the pattern of projection typical of nasal retina (all contralateral) to that typical of temporal retina (most ipsilateral) is much more gradual in the Siamese cat than in the normally pigmented cat, and is centred 1.7-3 mm temporal to the area centralis, instead of at the area centralis. In the Siamese cat only a few ganglion cells at the area centralis project ipsilaterally, as against nearly 50% in the normally pigmented cat. The proportion of ipsi-projecting cells reaches the 50% level 1.7-3.0 mm into temporal retina, and overall the zone of transition may be several millimetres wide, as against about 0.2-0.5 mm in in the normall pigmented cat. Evidence is presented that the degree of the abnormality of nasotemporal division varies between individual Siamese cats and that the abnormality is more severe among large or "giant" cells than among the population as a whole.

Cerebral abscess due to Listeria monocytogenes.

A case of cerebral abscess due to Listeria monocytogenes in a patient receiving immunosuppressive treatment is reported. Early diagnosis was facilitated by a cerebral scan.