CLINICAL NUCLEAR MEDICINE Volume 18, Number 5, pp 413-416 © 1993, J. B. Lippincott Co. Brain SPECT in a Patient With Post-Stroke ‘Hallucination S. M. KIM, M.D., C. H. PARK, M.D., C. M. INTENZO, M.D., AND J. ZHANG, Px.D. A patient developed visual hallucinations following a left-sided cerebrovascular accident (CVA). Brain SPECT using Tc-99m HMPAO demonstrated increased perfu- sion at the biparieto-occipital lobes. Following antiepi- leptic medication, repeat brain SPECT showed interval decrease in perfusion in the same areas with the symp- tomatic relief of hallucinatory episode. While it is possi- ble that the interval decrease is due to natural resolution, the authors believe that it is likely due to drug treatment. B™™ SPECT STUDY using N-isopropyl iodoamphet- amine (I-123 IMP) or Tc-99m hexamethylpropy- lene amine oxime (HMPAO) has been used success- fully for the evaluation of stroke, dementia, and seizure and psychiatric disorders (1-5). In 1988, Matsuda et al (6) reported an alcoholic patient with auditory hallucinations showing increased cerebral blood flow (CBF) in the left superior temporal area corresponding to the primary and secondary au- ditory centers. We report a post-stroke patient with visual halluci- nations inducing increased CBF on brain SPECT. Af- ter therapy with anti-epileptic medications, repeat brain SPECT indicated an interval decrease in CBE. Case Report A 70-year-old woman presented with a chief com- plaint of seeing “ghosts” for one month. She had no history of seizures and was not taking any antiseizure medications. She had a past medical history of hyper- tension, asthma, diabetes mellitus, and an old left CVA. Physical examination showed a fully alert, ori- ented woman with mild dementia and decreased short term memory. Language was not fluent but speech SS Received for publication May 15, 1992; revision accepted June 29, 1992, Reprint requests: S. M. Kim, M.D., Division of Nuclear Medi- cine, Thomas Jefferson: University Hospital, 11th and Walnut Streets, Philadelphia, Pennsylvania 19107. From the Department of Radiation Oncology and Nuclear Medicine, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania was not slurred. Pupils were equal, reactive to light, and extraocular muscle movement was intact, and there was no nystagmus or visual field defect. There was mild facial weakness with the tongue deviated to the right and soft palate raised, and there was a good gag reflex. The right upper and lower extremities showed mild motor weakness, sensory examination was normal, and finger-to-nose with dysmetria on the right was observed. Laboratory tests showed no anemia, electrolytes were normal, BUN 27 (normal 12-27 mg/dl), creatinine 1.7 (normal 0.7~1.4 mg/dL), glucose 79 (normal 60-110 mg/dL), calcium 9.2 (normal 8.5~10.5 mg/dL), phos- phate 3.5 (normal 2.5-4.5 mg/dL). Thyroid function tests, B-12, and folate levels were normal. Lyme titer was less than 0.8 (abnormal greater than 1). 24-hour electroencephalogram monitoring was free of abnor- mal seizure activity. The initial SPECT study was performed 2 days after the woman had been admitted to the hospital. SPECT imaging was obtained using a Triad triple-head detec- tor (Trionix Research Inc., Twinsberg, Ohio). Twenty millicuries of Tc-99m HMPAO were injected intrave- nously with the patient’s eyes closed under dim light in a noise free environment. Data was acquired into a 128 x 128 matrix, 40 steps (3° each) per each detector for 35 seconds per angle. After preprocessing data with the ramp filter, set to a cut-off frequency of 0.75/cm, the filtered back projection method was used for image reconstruction. Tomographic slices were analyzed along with three-dimensional reprojection images. Initial SPECT imaging, transaxial (Fig. 1, first and third rows) and sagittal slices (Fig. 2, first and third rows) demonstrated decreased perfusion in the left 413 414 .) « R frontal and temporal lobes as well as in the left basal ganglia (due to stroke) and decreased flow to the right cerebellum (due to crossed cerebellar diaschisis). There was marked increased perfusion in the occipito- parietal lobes bilaterally, which is likely due to seizure foci related to the visual hallucinations. The patient received antiseizure medications as well as a tranquil- izer. Six days later, a second SPECT study was per- formed; transaxial (Fig. 1, second and fourth rows) and sagittal views (Fig. 2, second and fourth rows) showed interval decreased perfusion within the occip- ito-parietal lobes and slight improvement of perfusion in the left frontal and left basal ganglia. At this time, the patient no longer was experiencing hallucinatory episodes. A CT scan of the patient performed three days after being discharged showed ischemic changes CLINICAL NUCLEAR MEDICINE May 1993 Vol. 18 Fig. 1. Initial transaxial slices (first and third rows) show marked increased cerebral blood flow (CBF) to the occipito-parietal cor- tices bilaterally (double arrows). Decreased CBF is evident in the left fronto-temporal and left basal ganglia due to stroke and in the right cerebellum. due to crossed cerebellar diaschisis. Posttreatment transaxial slices (second and fourth rows) depict interval de- crease in CBF to the occipito-parietal re- gions (arrows). : within the white matter and a lacunar infarction in the left basal ganglia. Discussion Cerebral blood flow studies can effectively be used to monitor changing events in seizure disorders. In- creased cerebral blood flow is now well documented during the ictal period of auditory hallucinations in an alcoholic patient (6). Our case shows increased blood flow during visual hallucinosis (organic hallucinosis). Continuous neuronal electrical firing is probably the cause of increased blood flow during the hallucina- tions. It is reported that the occurrence of acute visual hallucinosis, with the exception of peduncular halluci- nosis, can occur without a localizing focus within the No. 5 PATIENT WITH POST-STROKE HALLUCINATION . Kim et al 415 , Fig. 2. Initial sagittal slices (first row through the right hemisphere and the third row through the left hemisphere) reveal in- creased CBF to both occipito-parietal re- gions (open arrows). Repeat sagittal slices (second row through the right hemisphere and fourth row through the left hemisphere) demonstrate decreased CBF to the occipito- parietal cortices bilaterally (arrows). QVOdy central nervous system (7). The visual hallucination is associated with a lesion anywhere in the visual path- way. When the focus is in the temporal lobe, the complex stereotypical images are reported. When the focus is in the occipital lobe, brief stereotypical flashes of light or color are described. Because of the wide overlapping with symptoms originating in other re- gions, it is difficult to localize the focus on clinical ‘grounds, Brain SPECT has been used in monitoring the treat- ment response in the dementia of AIDS as well as in Alzheimer’s ‘dementia, Parkinson’s’ disease, and schizophrenia (8~11). Although it is possible that in- terval improvement could be due to spontaneous res- olution, we believe that interval improvement is more likely due to the drug treatments. The SPECT study, in this case report, proved to be very useful in both localizing visual hallucinations and in monitoring the therapeutic effect of antiseizure medications. References 1. Hill TC, Holman BL, Lovett R, et al: Initial experience with SPECT of brain using I-123 IMP. J Nucl Med 1982; 23:191- 195, 2. Katz, Rose A, Lind SJ and Spencer S: SPECT in patients with epilepsia partialis continua, Neurology 1990; 40:1848-1850. 3. Sharp P, Gemmell H, Cherryman G et al: Application of 1-123- labelled IMP imaging to the study of dementia. J Nucl Med 1986; 27:761-768. 4. Cohen MB, Graham LS, Lake R, et al: Diagnosis of Alzhei- mer's disease and multiple infarct dementia by tomographic imaging of 1-123-IMP. J Nucl Med 1986; 27:769-774. 5. LaFrance ND, Wagner HN Jr., Whitehouse P, et al: Decreased accumulation of isopropyl-iodoamphetamine in brain tumors. J Nucl Med 1981; 22:1081-1083, 416 6. Matsuda H, Gyobu T, Li M, et al: lodine-123 iodoamphetamine brain scan in a patient with auditory hallucination. J Nucl Med 1988, 29:558-560. 7. Geller TJ, Bellur SN. Peducular hallucinosis: Magnetic reso- nance imaging confirmation of mesencephalic infarction dur- ing life. Ann Neurol 1987; 21:602-604. 8. Rottenberg DA, Moeller JR, Satrother FW, et al: The metabolic pathology of the AIDS dementia complex. Ann Neurol 1987 22:700, CLINICAL NUCLEAR MEDICINE May 1993 Vol. 18 9. Pizzolato G, Dam M, Borsato N, et al: Te-HMPAO SPECT in Parkinson’s disease. J Cereb blood flow metabol 1988; 8:S101. 10. Smith FW, Gemmell HG, Sharp PF, et al: Tc-99m-HMPAO SPECT imaging in patient with basal ganglia disease. 1988 Br J Radiol 1988, 61:914. 11, Bajc M, Medved B, Basic M et al: Acute effect of electrocon- vulsive therapy on brain perfusion assessed by Tc-HMPAO and SPECT. Acta Psychiatr Scan 1989; 80:421.