To study the frequency, clinical features and clinical genetics of familial Parkinson’s disease (PD).

Family history for PD and tremors was studied in 100 consecutive PD cases. Spouses served as controls. Clinical features were compared between personally verified familial and sporadic PD cases, from the same consecutive clinical series. Clinical genetic analysis was performed in a larger group of non-consecutive multicase PD families.

Family history for PD was positive in 24% of consecutive PD cases and in 6% of spouse controls (p < 0.001). When family history for isolated tremor is also considered, the number of positive cases rises to 43% compared with 9% in controls (p < 0.001). Nine of the consecutive cases had at least one living affected relative, for a total of 20 familial PD cases. These familial cases showed an earlier onset age when compared with sporadic ones from the same consecutive series. Within 22 non-consecutive PD families with at least two living and personally examined PD cases (total 52 PD cases), the crude segregation ratios were similar for parents and siblings and the lifetime cumulative risks approached 0.4 in siblings and tended to be comparable, but at later ages, in parents. Ancestral relatives were all unilaterally distributed. In some families, anticipation of onset age in new generations was observed.

The frequency of positive family history for PD and for PD and tremor is higher among PD cases than controls. Familial and sporadic PD only differ in onset age. The clinical genetic analyses support autosomal dominant inheritance with strongly age-related penetrance as most likely in familial PD.

We have quantified the effects of levodopa treatment in Parkinsonian subjects during maintained stance.

Electromyographic muscle activity during quiet stance was assessed in subjects with Parkinson’s disease, who exhibited a fluctuating response to levodopa, and in age-matched control subjects. Stance stability was also assessed from mean displacement and velocity of the center of pressure excursions during stance.

Lower extremity and trunk muscles showed high amplitude activity in all Parkinson’s subjects when “off”, and a 4–5 Hz tremor in three of these subjects. When “on”, the amplitude of muscle activity was reduced in the distal muscles more than the proximal, while tremor was suppressed in all muscles. Corresponding to the excessive muscle activity, the Parkinson’s subjects had increased velocity and variability of velocity in the anterior-posterior center of foot pressure excursions, but the mean displacement of the center of pressure excursion was not different from the controls. The velocity of center of pressure excursions in the Parkinson’s subjects “on”, approached those of the control subjects suggesting that the excessive distal muscle amplitude and tremor contributed to the high velocity of the center of pressure.

These findings suggest that dopaminergic systems are involved in the regulation of muscle tone during stance. Depletion of dopaminergic transmission results in increased muscle tone and tremor in the lower extremities which may contribute to changes in posture and stability.

There is debate on the neurological impact of chronic exposure to Manganese (MN).

MN burden from rural well water was studied cross-sectionally in two proband cohorts from rural dwellings located in northern Germany. Both cohorts had exposure times for up to 40 years and were separated on the basis of well water MN content. Group A (41 subjects; mean age 57.5 years) was exposed to MN water contents of at least 0.300 mg/l (range 0.300 to 2.160), while group B (74 subjects; mean age 56.9 years) was exposed to concentrations of less than 0.050 mg/1. Both proband groups were homogenous with regard to age, sex, nutritional habits, and drug intake. Neurological assessments by clinical investigators blinded for proband’s exposure status was done using structured questionnaires, standardized neurological examination with assessment of possible Parkinsonian signs by the Columbia University Rating Scale, and instrumental tests of fine motor coordination.

No significant difference in any neurological measure was found between groups. Results were not confounded by demographic and dietary features.

Exposure to high body burden of MN does not result in detectable neurological impairment. Exposure to MN in drinking water does not seem to be a risk factor for idiopathic Parkinson’s disease.

To investigate the effects of aging and anoxia on the nucleus accumbens.

The number of neurons in nucleus accumbens and caudate neucleus in 35 patients over 65 and 35 under 65 years, all without neurological or psychiatric diseases were counted.

There was no statistically significant difference between the number of neurons in the accumbens in the two groups, but there was a decrease in the number of neurons in the elderly group. There was no reduction in volume of the neuronal nucleoli of the accumbens measured in 12 elderly patients compared to controls. These data suggest a sparing of the accumbens from changes associated with aging. There was relative preservation of the nucleus accumbens in 3 patients with anoxic encephalopathy.

These results show that accumbens was resistant to both aging and anoxia, the mechanism of which is discussed.

In order to explain the mechanism for the sparing of the nucleus accumbens in several pathologic conditions, the accumbens, caudate and putamen were examined in an experimental model.

The neurons in these regions from twenty adult rats were stained for the enzyme nicotinamide adenine dinucleotide phosphate (NADPH-diaphorase) and quantified.

Positive neurons in the nucleus accumbens were more abundant than in the caudate and putamen.

Since these neurons have been shown to be resistant to ischemia and degeneration, it is suggested that the mechanism for the sparing of the nucleus accumbens is related to the presence of a large number of NADPH-diaphorase positive neurons.

To assess the reliability of interictal spike discharge in routine electroencephalography (EEG) testing in children.

EEG results of all children diagnosed in Nova Scotia with epilepsy onset between 1977–85 (excluding myoclonic, akinetic-atonic and absence) were reviewed. The results of the EEG at time of diagnosis (EEG1) were compared with those of a second EEG (EEG2) within 6 months.

Of 504 children with epilepsy, 159 had both EEG1 and EEG2. EEG2 was more likely ordered if EEG1 was normal or showed focal slowing but less likely if EEG1 contained sleep (p < 0.05). EEG1 and EEG2 were both normal in 23%. If EEG1 was abnormal, there was a 40–70% discordance for the type of abnormality on EEG2. Abnormalities were present on both EEG1 and EEG2 in 67 cases. Of the 42/67 with major focal abnormalities on EEG1, 7 had only generalized spike wave on EEG2. Of the 17/67 with only generalized spike wave on EEG 1, 7 showed only major focal abnormalities on EEG2. Statistical testing showed low Kappa scores indicating low reliability.

The interictal EEG in childhood epilepsy appears to be an unstable test. A repeat EEG within 6 months of a first EEG may yield different and sometimes conflicting information.

In nine patients, suprascapular nerve palsy followed serious accidents associated with fractures of the cervical vertebrae, clavicle or scapula and after weight lifting, wrestling and a fall on the elbow or shoulder.

All patients were examined as to muscle wasting, weakness and shoulder fixation. EMG examination was done in all cases and six patients underwent surgical exploration.

The palsy was incomplete on clinical and EMG examination in all patients. On exploration, scarring, entrapment, tethering or kinking at the suprascapular notch was found in four and two had post-traumatic neuromas.

In contrast to published studies, none of our patients presented with shoulder pain, a spontaneous onset nor with involvement limited to the infraspinatus muscle. The differential diagnosis should include C5 root lesion, brachial plexus neuritis, frozen shoulder and tear of the rotator cuff.

Two cases of sudden unexpected deaths in patients with multiple sclerosis were investigated by the Office of The Chief Forensic Pathologist.

Case studies.

Marked similarities of the deaths, including circumstances, scene examination, and autopsy findings including a complete drug screen were recorded.

Exposure to high ambient temperature may pose a danger to patients with multiple sclerosis. Mechanisms of death and the potential dangers to patients with clinically widespread disease are discussed.

The evaluation and treatment of Jefferson fractures, a burst fracture of the ring of CI, has been well documented in the medical literature. Vertebral artery injury associated with a Jefferson fracture is very rare.

The case study technique was used to summarize the case. Review of the literature was performed to discuss the case. Retrospective chart review of the 174 patients with cervical fractures admitted to St. Michael’s Hospital from 1989–1994 was also performed.

The case of a patient with a Jefferson fracture, with bilateral lateral displacement of the lateral masses causing bilateral vertebral artery occlusions resulting in a lateral medullary and cerebellar infarction is reported. A review of the literature is provided.

A high index of suspicion for this injury is paramount, especially in patients with multiple trauma, where the diagnosis of Jefferson fractures can be delayed.

Tibial mononeuropathy due to compression by a synovial cyst is uncommon with fewer than 10 cases reported in the literature.

Case Study.

Tibial motor mononeuropathy with focal conduction block between the popliteal fossa and ankle was identified by electrophysiological testing. Magnetic resonance imaging and surgical exploration identified a synovial cyst compressing the nerve just distal to the popliteal fossa.

The combination of electrophysiological localization and imaging in cases of unexplained tibial mononeuropathy may identify an unexpected structural cause.

Ependymomas usually arise from the ventricular surface.

We report an 11-year-old female who presented with a supratentorial ectopic ependymoma.

The patient presented with a two-month-history of progressive headache, nausea and vomiting. Examination revealed papilledema, horizontal nystagmus, diplopia on upward gaze, and right pronator drift. CT scan showed an enhancing left precentral subcortical lesion measuring 3 cm in diameter with associated edema and mass effect. Its medial border was located 3 cm from the ependymal surface of the ventricle. A firm tumour was dissected from the centrum semiovale white matter, and removed in toto as confirmed on MRI. Pathological examination revealed histological, immuno-histochemical and electron microscopic features consistent with an ependymoma. Spine MRI and bone marrow aspirate, as well as lumbar puncture of cytology failed to show any dissemination.

From the literature review, this represents an exceptional ependymoma located at the distance from the ventricular system or cisterns. Different pathogenic alternatives are discussed.

Herpes simplex encephalitis usually has a progressive cause. Sudden neurological deficits are unusual.

Case study.

A 17-year-old girl presented with an acute onset focal neurological deficit followed one week later by the more classical feature of altered level of consciousness, fever and focal seizures. The diagnosis of hepetic encephalitis was made by magnetic resonance imaging (MRI) and by the significant increase in cerebrospinal fluid titres of antibodies against herpes simplex type I.

Herpetic encephalitis should be considered in the differential diagnosis of acute stroke in young patients even in the absence of encephalitic features, if common etiological factors such as embolization and intracerebral bleed are excluded.