Biomedical subjects
Publications and source records attributed to M Wall.
At age 3 1/2 years a child developed what appeared to be classic spasmus nutans. Thorough discussions as to the propriety of neuroimaging studies in such patients are presented. With this late age of onset, the presence of a compressive lesion was suspected and neuroimaging demonstrated a sellar-suprasellar mass lesion.
A young woman became suddenly aware of visual loss in her left eye. She was found to have optic atrophy giving chronicity to the disease process. A hypopigmented macule on her face along with neuroimaging studies suggested an inflammatory process. A biopsy of the skin lesion was compatible with sarcoidosis. The patient responded to corticosteroid therapy.
A 58-year-old healthy man presented with a history of monocular visual loss with incomplete recovery. The differential diagnosis, evaluation, and possible therapeutic interventions are discussed. The presenter controversially felt that although the source of embolic material was likely ipsilateral carotid artery and no evaluation was necessary.
A patient with unilateral optic neuritis with CT evidence of optic nerve enlargement and reduction in nerve size treatment is reported.
A 43-year-old man with high blood pressure developed visual loss in his left eye. He was found to have bilateral disk edema with cotton wool spots present in the temporal arcades and peripapillary hemorrhages. The presence of the cotton wool spots in the arcades is highly suggestive of hypertension as the etiology of the disk edema. The pathophysiology of cotton wool spots (inner retinal ischemic spots) due to focal ischemia from occlusion of terminal retinal arterioles is discussed.
A patient with elevated intracranial pressure from aqueductal stenosis presented with unilateral disk edema, enlarged blind spot and a vague visual disturbance. The importance of considering elevated intracranial pressure in some cases without bilateral papilledema is emphasized.
A young woman presented with the recent onset of an inability to move the eyes on a horizontal plane. Examination revealed limited horizontal gaze to the right and a complete left ophthalmoplegia. The limitation of eye movement could not be overcome by the doll's head maneuver. Other signs included bilateral orbicularis oculi weakness and brisk deep tendon reflexes. Her condition gradually improved and two months following the onset of the illness she was symptom free.
Three cases of a stroke syndrome of acute supranuclear vertical gaze ophthalmoplegia are presented. Voluntary vertical gaze and the vertical vestibulo-ocular reflex were absent or diminished initially in all three patients. The patients also had loss of convergence and alteration in their mental status. Computed tomography scans showed lesions in the region of the rostral midbrain and lower diencephalon in the area surrounding the third ventricle. The blood supply, ischemic stroke syndrome and function of this region with reference to the supranuclear control of vertical gaze are discussed.
Human spermatozoa readily undergo in vitro capacitation and the acrosome reaction when exposed to a single, brief, high-voltage electric pulse in a medium containing calcium. Using the fluorescent calcium indicator, Fura-2, the changes in the intracellular calcium concentration of human sperm following exposure to voltages in the range of 200-2000 V cm-1 were measured. The induction of the acrosome reaction by the electropermeabilization pulse was also monitored. In comparison, changes in calcium uptake during a standard capacitation procedure in which sperm samples were incubated for 7 h were analyzed. At hourly intervals, acrosome reaction induction and intracellular calcium uptake were measured. The results indicate that electropermeabilization rapidly and efficiently produces high populations of acrosome-reacted sperm and a corresponding and associated increase in the intracellular calcium concentration.
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A 17-year-old, castrated male domestic shorthair cat presented with nonspecific clinical findings of three days' duration. Complete blood counts and serum biochemistry profiles revealed evidence of hepatic dysfunction. Ultrasonographic evaluation revealed abnormalities consistent with pancreatitis, with suspected pancreatic duct dilatation in the left limb of the pancreas. Surgery and eventual necropsy confirmed a diagnosis of pancreatitis, along with pancreatic duct dilatation. Dilatation of the pancreatic duct may be another ultrasonographic change to look for when suspecting feline pancreatitis.
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A thalamic infarct in a 65-year-old woman was initially imaged as a discrete low-density mass in the left side of her thalamus by CT. Abnormal MR signal was also noted in the thalamus and midbrain. Follow-up imaging showed nearly complete resolution of the low-density lesion on CT and the abnormal signal on MR.
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