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Biomedical subjects

D H Yock

Publications and source records attributed to D H Yock.

17 recordsLinked to original sources

Bilateral periventricular nodular heterotopia with mental retardation and syndactyly in boys: a new X-linked mental retardation syndrome.

Bilateral periventricular nodular heterotopia (BPNH) is a recently recognized malformation of neuronal migration, and perhaps proliferation, in which nodular masses of gray matter line the walls of the lateral ventricles. Most affected individuals have epilepsy and normal intelligence with no other congenital anomalies. A striking skew of the sex ratio has been observed because 31 of 38 probands have been female, and one gene associated with BPNH was recently mapped to chromosome Xq28. We report three unrelated boys with a new multiple congenital anomaly-mental retardation syndrome that consists of BPNH, cerebellar hypoplasia, severe mental retardation, epilepsy, and syndactyly. Variable abnormalities included focal or regional cortical dysplasia, cataracts, and hypospadius. We hypothesize that this syndrome involves the same Xq28 locus as isolated BPNH, and we review the expanding number of syndromes associated with BPNH.

Adolescent↗

Imaging of intracranial infection.

Modern imaging techniques define the anatomic region infected and the evolution of the disease, help to evaluate treatment efficacy, and frequently can help to determine extra-central nervous system sources of infection, such as sinusitis or mastoiditis. These techniques are discussed by anatomic region, and differential diagnosis based on image pattern is formulated. Special attention is given to the findings in the immunocompromised host and in congenital infection.

Acquired Immunodeficiency Syndrome↗

Redundant lumbar nerve root syndrome: myelographic features.

Nine patients with redundant lumbar nerve root syndrome were identified using positive-contrast myelography, seven with metrizamide and two with iophendylate. Serpiginous intradural filling defects occurred in conjunction with a complete or partial extradural block and spinal stenosis. These redundant nerve roots were seen on the cephalic side of the block. Eight of the nine patients had pseudoclaudication. One case was found incidentally during a cervical myelogram. This series is presented to demonstrate the characteristic myelographic pattern that should be recognized and differentiated from tortuous intradural blood vessels. Possible causes are discussed.

Adult↗

CT demonstration of cerebral emboli.

Four cases of cerebral emboli diagnosed on computed tomography as foci of increased density are discussed. The emboli were calcified in at least two cases. Both cardiac and carotid sources contributed dense emboli, which were seen to lodge at typical scan sites: near the anterior cerebral artery bifurcation (two cases) and in the middle cerebral artery horizontal segment-trifurcation region (two cases).

Aged↗

Choroid plexus lipomas associated with lipoma of the corpus callosum.

Lateral ventricular choroid plexus lipomas are frequently associated with lipomas of the corpus callosum. Choroid plexus lipomas may be continuous with the midline lesion or discrete, and they may be bilaterally symmetrical of asymmetrical. The case of a 9-month-old infant is presented as an example.

Brain Neoplasms↗

Computed tomography of hemorrhage from anterior communicating artery aneurysms, with angiographic correlation.

The CT findings in 19 cases of ruptured anterior communicating artery aneurysms are analyzed and compared to the angiographic appearance. Observations from this series and literature review include (a) occasional negative scans, (b) visualization of non-giant aneurysms on infused axial scans, (c) common asymmetric subarachnoid hemorrhage, (d) involvement of the anterior interhemispheric fissure whenever subarachnoid hemorrhage is visualized, (e) "typical" septal hematoma in a minority of cases, (f) frequent infarction, particularly in the anterior cerebral artery distribution, (g) "meningeal hyperemia" seen on post-contrast scans, and (h) little correlation between angiographic aneurysm orientation and the location of hemorrhage on CT scan.

Adult↗

Early diagnosis of delayed posttraumatic intracerebral hematomas.

Nine cases of delayed posttraumatic intracerebral hematomas (DTICH) were found retrospectively among 656 patients with closed head injuries admitted to the Hennepin County Medical Center in a 12-month period. All cases had severe head injuries sustained with the head in motion. The interval from cranial injury to diagnosis of DTICH by computerized tomography (CT) varied from 8 hours to 13 days. Eight patients were comatose on admission, three had focal seizures, and three had focal findings. The diagnosis was made on repeat CT scans obtained because of the development of focal findings in four cases, lack of improvement in four cases, and general neurological deterioration in one case. Four patients had initially negative CT scans. Four demonstrated only extracerebral hematomas on initial CT scan. One patient showed intracerebral hematoma on the initial scan followed by new hematomas on repeat study. The cases presented are discussed in light of pertinent literature.

Accidents, Traffic↗

Recent ischemic brain infarcts at computed tomography: appearances pre- and postcontrast infusion.

Thirty-seven cranial computed tomography (CCT) scans of proved or highly probable recent ischemic brain infarcts were analyzed visually and numerically, with results organized by infarct age. The lesions typically appeared as homogeneous low density abnormalities, with no significant difference in scan characteristics between infarct age groups, i.e., it was not possible to determine the age of an infarct by its noninfused, CCT appearance alone. Eight infarcts showed "mass effect," and 4 of the 20 contrast-infused cases demonstrated marked density augmentation of "blush," indicating that infarcts may resemble tumor in both of these properties.

Adolescent↗

Spinal subarachnoid hematoma after lumbar puncture producing acute thoracic myelopathy: case report.

A case of subarachnoid hematoma after a difficult lumbar puncture and anticoagulation is presented. Subarachnoid adhesions preventing the free flow of spinal fluid at the T-6 level served to limit the cranial progression of the hemorrhage and produced a transverse myelopathy at that level. The underlying pathology, clinical course, and myelographic findings are reviewed. Pertinent literature is presented.

Back Pain↗