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Show f. Clill. Neuro-ophthalmol. 4: 251-253, 1984. Cerebral Infarction and Subdural Hematoma Advantage of Nuclear Magnetic Resonance Imaging in Cerebral Ischemia ALEXANDER MAUSKOP, M.D. ARTHUR H. WOLINTZ, M.D. RAMON VALDERRAMA, M.D. Abstract Visual hallucinations were the initial complaints in a patient with a posterior cerebral artery occlusions who fell and sustained bilateral subdural hematomas. In addition to poor vision, the patient experienced formed visual hallucinations of the epileptic type in the hemianopic field. The hemianopia was dense with macular sparing. CAT scans, which were done pre- and postoperatively, showed no abnormalities in the temporal and occipital lobes to explain the "epileptic visual hallucinations" and macular sparing. The NMR scan showed low-density changes in those areas. At the time that the NMR scan was done, most of the patient's deficits, including the hemianopia and hallucinations, had resolved. Nuclear magnetic resonance (NMR) imaging is becoming a valuable study to determine the existence of structural disease of the brain. In addition, NMR imaging may indicate the presence of cerebral dysfunction when computed tomography fails to establish a pathologic process. We describe a patient with clear-cut NMR abnormalities when the CAT scan failed to correlate clinically with the patient's findings. Case Report A 68-year-old diabetic, hypertensive man presented with complaints of sudden onset of poor vision and headache. These symptoms began after a syncopal attack 3 weeks earlier. The syncopal attack was attributed to hypoglycemia, as the patient stated that a packet of sugar made him feel better. The headache was not severe, but Fwm the Departments of Neurulogy Jnd OphthJlmology, State University of New York; and Downst,1tc Ml'dical Center, Bwoklyn, Ne~ York. December 1984 constant and bregmatic in location. Vision was worse in the left eye and impaired his ambulation, however, some of the difficulty in walking he attributed to mild left-sided weakness. While being examined, the patient suddenly turned his eyes to the left, stopped talking, but was able to answer questions, and said that he was visualizing little people dancing on the left side. During this episode he was able to bring his eyes over to the opposite side. He admitted to having these episodes, lasting from minutes to several hours, quite frequently during the previous 3 weeks. He had stopped his usually heavy alcohol intake after the onset of these symptoms 3 weeks earlier. On physical examination, he was alert and oriented and remembered two out of three objects after 5 minutes. Cranial nerve examination revealed a dense left homonymous hemianopia with macular sparing. Visual acuity with best correction was 20/30 in each eye. Neck was supple with no carotid bruits. Examination of pain, touch, vibration, and joint position sense was normal. Motor examination revealed mild (4/5) left hemiparesis. He walked with a limp, although it was apparent that his walking was impaired because of a visual defect. DTRs were 1+ and symmetrical. Babinski sign was absent. laboratory data included a serum glucose of 448 mgj dL. The following studies were normal: BUN, Cr, Cl, K, Na, Hct, Hgb, WBC, PT, PTT. EEG showed slowing of the background and an electrographic seizure localized to the right hemisphere. Unfortunately, clinical correlation was not made during this seizure. CAT scan (Fig. 1) demonstrated a right frontoparietal subdural hematoma, moderate in size, with a blood-fluid level and a small left frontal subdural hematoma. A mild right to left shift of the midline structures was seen. The right subdural hematoma was evacuated, but a postopertive CAT scan showed recollection of the SDH. Repeat surgery was performed with persistent resolution of the clot as confirmed by a CAT 251 Cerebral Infarction and Subdural Hematoma Figure 2. CAT scan at the time uf NMR scan (withuut contrast) scan done 5 weeks later (Fig. 2). None of the CAT scans showed any abnormality in the right occipital or temporal lobes. Six weeks after admission the patient underwent NMR imaging. (FONAR Beta 3000, static magnetic field 0.2795, spin echo sequence, long tau = 55 msec, repetition period = 1.80 sec, number of averages = 1, pulsing sequences were same for both scans.) By the time the NMR imaging study was performed, the patient had experienced an episode of pulmonary embolism, which was treated successfully, but his neurological status had markedly improved. There was a less dense field defect, the seizures (visual hallucinations) had stopped, and his strength had improved. NMR scan (Fig. 3) showed a large area of decreased density in the right temporo-occipital region. 252 Discussion Homonymous hemianopia with macular sparing, as seen with an infarction of the occipital lobe, has been well described in patients with subdural hematomas. 1 It usually is the result of transtentorial herniation with compression of the posterior cerebral artery. Our patient had no clinical or CAT scan evidence of herniation and his SDH was anterior in location. Formed visual hallucinations usually occur with temporal lobe lesions. The most likely course of events in this patient was as follows: the occlusion of the right posterior cerebral artery was accompanied by transient ischemia of the brain stem that resulted in loss of consciousness, which in turn resulted in a fall and subdural hematomas, with contusion of the right temporal lobe. Journal of Clinical Neuro-ophthalmology Mauskop, Wolintz, Valderrama Figure 3. '\r-..1R sC<ln The formed visual hallucinatiuns were probably of the epileptic type seen with temporal lobe lesions rather than release hallucinations occasionally seen c with a posterior cerebral artery occlusion. Evidence or that is the abrupt onset of hallucinations with contraversive eye movement and an electrographic seizure on EEG NMR imaging has been reported to be abnormal in patients with reversible cerebral ischemia, while the CAT scan was normal.' Early ischemic changes in experimental animals can also be detected by NMR imaging.4' One explanation relates to the increase in water content in the ischemic region which is not sufficient to produce x-ray density changes, but may be visualized by NMR imaging. Our patient had a lesion no longer apparent clinically that was never seen on CAT scans, but visualized by NMR imaging. This report of a patient with a subdural hematoma and extraordinary clinical findings also confirms the belief that NMR imaging is superior to computerized tomography for the detection of cerebral ischemia, which may be reversible. References I. Hoyt. W.F.: Vascular lesions of the visual cortex with brain herniation through the tentorial incisura. Arch. Ophthalmol. 64: 74-86, 1960. December 1984 2 Brust. .I.e. 1.. ilnd Behrens, MJv1 .. " Rt!lease hallucinatillns" a~ the maJor s\'mptom lli pllsterior cerebr. 1l arll'n' llcclusion: A reporl tli 2 c.1ses. AIIII. Nellro!. 2: 432-436, 1977. 3. Sipponen, J T., Kaste, M.. Sepponen, R.E, Kuurne, T., SULlT.1nla, Il, .1nd Sivula, A.: Nuclear magnetic resonanCl' imaging in reversible cerebral ischaemia. Llll/t'c! 1: 244-295. ]983. 4 Buonannll, r:'s. Kistler. J P., Br<ld\', TJ., el al.. Prottlll !\:~m im.1ging in experimental ischemic cerebral iniarllion. hullS. Alii. .\"·lIr"I. Ass,'(. 106: 50-53,1981 5. Spetzler, R.F., Zabramski, ).M., Kaufman, B., and Yeung, H.N.: Acute NMR changes during MCA occlusion: A preliminary study in primates. Stroke 14(2): 185-191. 1983. Acknowledgments The authors thank FONAR Corporation for performing the NMR imaging study; and Mark Weiner, M.D., for assisting in the care of the patient. Write for reprillt, to: Alexander Mauskop, M.D., Department of Neurology, Memorial Sloan-Kettering Cancer Center, )275 York Avenue, New York, New York 10021 253 |
