SUMMARY A disinhibition syndrome affecting speech (with logorrhoea, delirium, jokes, laughs, inappropriate comments, extraordinary confabulations), was the main manifestation of a rightsided thalamic infarct involving the dorsomedian nucleus, intralaminar nuclei and medial part of the ventral lateral nucleus. Resolution of conflicting tasks was severely impaired, suggesting frontal lobe dysfunction. These abnormalities correlated with the finding on SPECT of a marked hypoperfusion in the overlying hemisphere predominating in the frontal region. We suggest that this behavioural syndrome was produced by disconnecting the dorsomedian nucleus from the frontal lobe and limbic system. Unilateral non-haemorrhagic infarcts limited to the non-dominant thalamus are uncommon. Moreover, they may be missed, because they may give rise to non-focal disturbances, such as impairment of consciousness, acute confusional state, or apathy, without major focal neurological or neuropsychological findings. We report a patient with a right thalamic infarct, whose main disturbance was a disinhibition syndrome mainly affecting speech, which mimicked an acute manic delirium. The findings of a marked hypofusion in the overlying hemisphere predominating in the frontal region suggested a cortical deafferentiation due to the thalamic lesion.Case report A 72 year old right-handed housewife was admitted to hospital after she suddenly became somnolent. She never smoked and was not known to be hypertensive. She had no past history of psychiatric illness or stroke. The morning of admission, she was found by her husband on the floor of the bathroom, somnolent and confused. On examination the same day, she was drowsy but easily arousable; she was disoriented in time and place. Blood pressure was 150/90 mm Address for reprint requests:

Two patients with bilateral thalamo-mesencephalic infarct in the paramedian territory developed vertical gaze dysfunction and marked behavioural changes, in the absence of significant motor inability and formal neuropsychological impairment. While they were physically and emotionally active before stroke, they became apathetic, aspontaneous, indifferent, and seemed to have lost motor and affectic drive, as well as the need itself for any psychic activity. However, this mental and motor inertia was reversible when the patients were repeatedly stimulated by another person. This need for constant external programming, together with a lack of emotional reactivity, made the patients resemble robots. CT and MRI suggested involvement of the dorsomedial and midline nuclei of the thalamus, and SPECT showed remote frontomesial hypoperfusion. A disturbance of the striatal-ventral pallidal-thalamic-frontomesial limbic loop is suggested by previous reports of a similar "loss of psychic self-activation", "pure psychic akinesia", or "athymhormia" with bipallidal, bistriatal, or subcortical bifrontal lesions.

Many patients suffer a stroke early after a transient ischemic attack, but the reason why is often unclear. We studied 12 patients with <75% stenosis of the internal carotid artery and a single hemispheric transient ischemic attack lasting <1 hour who had a normal neurologic examination 3-13 hours later and a normal computed tomogram 24-36 hours later. Singlephoton emission computed tomography using technetium-99m HM-PAO ^50 hours after the attack showed no abnormality in eight patients, but in the other four there was an area with 30-50% reduction in perfusion ipsilateral to the transient ischemic attack. Three of these four patients developed an ipsilateral infarct 3-7 days later, but none of the eight patients with normal single-photon emission computed tomograms had a stroke during the following weeks. No difference in therapy, risk factors, severity of internal carotid artery disease, or timing of the technetium-99m study could explain these findings. We suggest that some transient ischemic attacks, though clinically identical to others, may be associated with persisting focal hypoperfusion, which predisposes to early stroke. -2 because its relation to the duration of clinical symptoms and signs varies. We used single-photon emission computed tomography (SPECT) to study 12 patients with one isolated TIA lasting <1 hour and found that persisting focal hypoperfusion after resolution of TIA symptoms may be associated with early infarction in the same area. Subjects and MethodsThe aim of our study was to assess SPECT findings early after a brief and unique TIA. As most TIAs lasting >1 hour may actually correspond to true infarction (cerebral infarction with transient signs [CITS], including TIA due to lacunar infarction), 3 entry into the study was limited by preestablished policy to patients whose symptoms lasted <1 hour and who had a normal neurologic examination ^12 hours after the TIA. Because previous cerebrovascular events could also confuse the findings, we selected only patients with a single TIA in the carotid territory, without any history of a prior TIA or stroke. Symptoms of carotid-territory TIAs were defined as motor hemiparesis with or without hemisensory or homonymous hemianopsic impairment and aphasic disturbance with or without motor or sensory distur- bances. We also excluded patients with ^75% stenosis (internal carotid artery [ICA] systolic peak >8 KHz with spectral broadening, decreased diastolic window, and increased diastolic frequency) 4 or occlusion of the ipsilateral ICA demonstrated by extracranial carotid and transcranial Doppler ultrasounds because ICA or middle cerebral artery (MCA) occlusion or ^75% stenosis may in itself cause ipsilateral cerebral hypoperfusion. Brain computed tomography (CT) with or without contrast was performed at least 24 hours after the TLA to exclude patients with visible cerebral infarction. Electrocardiography (ECG) with 24-hour monitoring and two-dimensional echocardiography were also performed to rule out an undetected cardiac source of embolism. The c...

Miscellaneous cardiac abnormalities can occur after electrical burns. The long term outcomes are still unknown. We studied 10 patients, 9 of whom suffered high-voltage electrocution, and one of whom was struck by lightning. Serial electrocardiograms (ECG) and serum MB creatine phosphokinase isoenzyme (MB-CPK) activities were obtained during their stay in hospital. ECG and thallium 201 cardiac scintigraphy at rest, as well as echocardiograms were obtained in all patients 4 to 48 months after discharge. In hospital, 9 patients showed one or more abnormal findings at physical examination (4 cases), ECG (8 cases), MB-CPK (1 case). At long term follow-up, 5 patients had one or more myocardial functions or conduction abnormalities, with or without symptoms. One patient had compensated heart failure. Nine patients were asymptomatic. Abnormal ECG findings persisted in 3 patients. Three cardiac scans showed evidence of regional myocardial hypoperfusion. Decreases in left ventricular indices measured by echocardiogram were found in 3 patients. We conclude that high-voltage electrocution is associated with a high incidence of cardiac abnormalities, which may persist. Long term evaluation, requiring cardiac T1 201 scintigraphy and echocardiogram, may be justified.

99mTc-Hydroxymethylene diphosphonate (HMDP) was compared to 99mTc-methylene diphosphonate (MDP) with respect to image quality, lesion detectability, and the uptake ratios of normal bone to soft tissue (B/S), metastatic bone to soft tissue (M/S) and bone metastases to normal bone (M/B) at 2 and 3 h after injection in the same subjects. Thirty-three patients with bone metastases were examined in six nuclear-medicine departments, with each center using its usual bone-scanning protocol which was identical for both compounds in the same patient. The uptake of 99mTc-HMDP in normal bone (B/S) was significantly higher than that of MDP at 2 and 3 h, but there were no significant differences between the two compounds with regard to the M/S or M/B ratios. The M/B of HMDP at 2 h was not significantly different from that of MDP at 3 h, the latter showing a significantly higher B/S and M/S ratio. All lesions were detected with both compounds, even at 2 h. The image quality was rated as follows (in decreasing order): HMDP (3 h), MDP (3 h), HMDP (2 h), and MDP (2 h). HMDP was shown to be a useful bone-imaging agent, especially when shorter intervals between injection and recording are required.