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S G Pavlakis

Publications and source records attributed to S G Pavlakis.

12 recordsLinked to original sources
PubMed1992

Melas: an original case and clinical criteria for diagnosis.

We describe the full history and postmortem findings in one of the first identified cases of mitochondrial encephalomyopathy with stroke-like episodes (MELAS). To clarify diagnostic criteria, we analyzed 69 reported cases. The syndrome should be suspected by the following three invariant criteria: (1) stroke-like episode before age 40 yr; (2) encephalopathy characterized by seizures, dementia, or both; and (3) lactic acidosis, ragged-red fibers (RRF), or both. The diagnosis may be considered secure if there are also at least two of the following: normal early development, recurrent headache, or recurrent vomiting. There are incomplete syndromes in relatives of patients with the full syndrome and incomplete syndromes might also be encountered in sporadic cases. Some MELAS patients have features of the Kearns-Sayre syndrome (KSS) or myoclonic epilepsy with ragged-red fibers (MERRF), but none had the full KSS syndrome. In partial or confusing cases, analysis of mitochondrial DNA (mtDNA) may point to the correct diagnosis; however, not all patients with clinical MELAS have had the typical mtDNA point mutation and some patients with the mutation have clinical syndromes other than MELAS.

Brain↗
PubMed1992

Fanconi anemia: a model for genetic causes of abnormal brain development.

Fanconi anemia is an autosomal recessive disease resulting in bone-marrow failure, phenotypical abnormalities and predisposition to malignancy. The authors reviewed 257 clinical and neuropathology results from the International Fanconi Anemia Registry at The Rockefeller University. Two patients had hydrocephalus and ventriculoperitoneal shunts. Of 15 neuropathology reports, 10 found CNS abnormalities, with the most common--ventriculomegaly--seen in six, two of whom required shunts. Aqueductal stenosis, agenesis of the corpus callosum and septum pellucidum, and holoprosencephaly were found. The authors conclude that neurological derangements are probably more common in Fanconi anemia than previously recognised. Fanconi anemia cells in culture are highly sensitive to oxidative stress and alkylating agents; Fanconi anemia may provide a model for a genetic disorder potentially predisposing to environmental insults.

Abnormalities, Multiple↗
PubMed1991

Steroid-responsive chorea in moyamoya disease.

We report the case of a 13-year-old boy with disabling chorea due to moyamoya disease. His chorea seemed to improve with steroid therapy. We conclude that steroid therapy may ameliorate moyamoya-associated chorea, and perioperative steroids can confound neurosurgical outcome. We are unable to assess the effect of cerebrovascular bypass procedures on the outcome of chorea in this patient.

Adolescent↗
PubMed1991

Middle cerebral artery blood velocity and cerebral blood flow in sickle cell disease.

To understand better the relationship between blood velocity measured by transcranial Doppler and cerebral blood flow measured by the 133Xe inhalation method, we examined 23 patients undergoing evaluation in the Comprehensive Sickle Cell Center at Columbia University. Blood velocity in the middle cerebral artery was directly related to cerebral flow (r = 0.77; p less than 0.05). A multivariate analysis in this sample made it possible to improve this correlation to account for more than 90% of the variability in cerebral blood flow by the use of transcranial Doppler measures of velocity and pulsatility along with the patient's age and hematocrit (r = 0.95; p less than 0.001). It is likely that the combination of Doppler and clinical or demographic variables in other diseases will similarly improve the quantitative estimation of cerebral blood flow.

Adolescent↗
PubMed1991

Hypothalamic-midbrain dysregulation syndrome: hypertension, hyperthermia, hyperventilation, and decerebration.

Certain decerebrate lesions of brain stem or hypothalamus induce pharmacologically reversible hypertension and hyperthermia in animals. We observed three young patients with episodic decerebration, hyperthermia, hypertension, and hyperventilation during recovery from comas of different etiologies. The shared pathology on neurologic examinations and computed tomographic scans was hypothalamic-mesencephalic dysfunction, suggesting a diencephalic-brain-stem disconnection syndrome or brain-stem release mechanism. Propranolol was the most effective drug tested, but only two patients responded, one dramatically. This novel clinical syndrome may have localizing and therapeutic significance in pediatric coma that needs to be further defined in future studies.

Adolescent↗
PubMed1991

Stroke in children.

Childhood stroke, although similar to adult stroke, is characterized by congenital and genetic causes. The evaluation and treatment of the child with stroke requires special considerations. Currently, drug therapy is untested and as a result, therapeutic interventions are problematic. Platelet antagonists are rational prophylactically; warfarin probably has a role in preventing cardiogenic embolus in the older child. However, chronic anticoagulation in the toddler is dangerous due to frequent trauma and is therefore relatively contraindicated. Vascular malformations are surgically repaired but alternative therapies, including radiation and embolization, may be used for inoperable lesions. Aneurysms are primarily surgical lesions. Newer imaging modalities will clarify the pathophysiologic picture and improve treatment.

Brain↗
PubMed1989

Epilepsy "cure".

Explore the source record for details and available documents.

Epilepsy↗
PubMed1989

Cerebral hyperemia, stroke, and transfusion in sickle cell disease.

To investigate cerebral hemodynamics in sickle cell disease (SCD), we used the 133Xenon inhalation technique of quantifying cerebral blood flow (CBF) in 67 patients. Clinical examinations and cerebral magnetic resonance imaging also were performed in all patients. Compared with age-matched healthy controls, CBF was elevated by 68% in patients, and inversely related to hematocrit. An experimental index of cerebral blood volume, pr4, was also elevated in the patients in a similar manner. Cerebral blood volume was positively correlated to CBF in SCD patients but not in controls. History of stroke and current neurologic symptoms were associated with lower flow and higher cerebral blood volume. Transfusion therapy reduced the hyperemia, the reduction being greater than expected by hematocrit elevation alone. These findings document a vasodilatory hyperemia in SCD. This dilatation may be a risk factor for ischemic distal-field infarctions, as visualized by MRI, due to a limitation of cerebrovascular reserve capacity.

Adolescent↗
PubMed1988

Brain infarction in sickle cell anemia: magnetic resonance imaging correlates.

Brain infarction is a well-known but poorly understood complication of sickle cell disease. Seventy-three sickle cell disease patients underwent neurological examinations and high-field, heavily T2-weighted axial cranial magnetic resonance image (MRI) scanning. Eighteen of the 73 had a history of stroke, defined as an acute, focal neurological sign lasting longer than 1 hour; in the event of a convulsive onset, an MRI abnormality as a correlate was necessary. Sixteen of the 18 stroke patients demonstrated focal MRI abnormalities consistent with arterial borderzone infarctions. Fifty-five of the 73 patients had no history of stroke. Six of the 55 (11%) had focal MRI abnormalities suggesting previous subclinical stroke. Five of these lesions were in borderzone regions. The distinguishing feature in 21 of the 22 patients with MRI abnormalities was the predilection for lesions in the high cortical convexity, in the general regions of arterial borderzones between the major cerebral arteries and adjacent deep white matter. The pattern of MRI lesions suggests two pathogenetic mechanisms: (1) proximal large-vessel disease with inadequate cerebral perfusion (distal field insufficiency syndrome) and (2) distal small-vessel disease (sludging syndrome).

Adolescent↗
PubMed1988

Transcranial Doppler measurements of the middle cerebral artery. Effect of hematocrit.

We evaluated the effects of hematocrit on blood velocity in the middle cerebral artery measured by transcranial Doppler ultrasonography in 45 patients. Hematocrits ranged from 16% to 46%, and systolic blood velocities ranged from 70 to 190 (mean 40 to 140) cm/sec. Decreases in hematocrit correlated with increases in blood velocity in the middle cerebral artery. These results suggest that transcranial Doppler measurements made in the presence of anemia may need correction.

Adolescent↗