Successful hemispherotomy in two refractory epilepsy patients with cerebral hemiatrophy and contralateral EEG abnormalities

We describe two cases of refractory epilepsy with cerebral hemiatrophy and contralateral electroencephalographic (EEG) abnormalities, in which hemispherotomy of the atrophic hemisphere effectively controlled seizures. Case 1 was a 5-year-1-month-old girl with refractory bilateral asymmetrical tonic posturing seizures predominantly in the right arm. Magnetic resonance imaging showed left porencephaly corresponding to a left middle cerebral artery infarction. Case 2 was a 3-year-8-month-old boy with refractory bilateral asymmetrical tonic posturing seizures predominantly in the right arm due to atrophy of the left cerebral hemisphere after septic meningitis. Both patients had right hemiparesis and was incapable of pinching by the right hand. Contralateral interictal and ictal EEG abnormalities were observed. Interictal ^99mTc-ethyl cysteinate dimer (^99mTc-ECD) single photon emission computed tomography (SPECT) showed hypoperfusion and ictal ^99mTc-ECD-SPECT showed hyperperfusion within the left cerebral hemisphere. Left hemispherotomy was performed. Cases 1 and 2 remained seizure-free at the last follow-up 18?months and 15?months, respectively, after surgery, and contralateral interictal EEG abnormalities disappeared. In patients with cerebral hemiatrophy and contralateral EEG abnormalities, epilepsy surgery may be considered when the laterality of seizure semiology, functional imaging findings and motor deficits were concordant with the atrophic side. Ictal SPECT is effective to confirm the epileptogenic hemisphere.     

A case of hemimegalencephaly with slowly progressive expansion

We report a case of a male infant with refractory epilepsy, demonstrating hemimegalencephaly with slowly progressive expansion. The patient experienced his first seizure at 4 months of age. Subsequently, tonic seizures occurred very frequently despite extensive antiepileptic medications, and his development deteriorated. Cranial magnetic resonance imaging (MRI) at 4 months of age showed focal cortical dysplasia in the right opercular area. This focal lesion gradually expanded, and became thickened. Five years later, the dysplastic lesion occupied most of the right cerebral hemisphere and the volume of the right hemisphere increased, indicating hemimegalencephaly. He had profound motor and intellectual retardation. In the abnormal cerebral hemisphere, fluorodeoxyglucose-positron emission tomography (FDG-PET) showed marked hypometabolism, and ictal single photon emission computed tomography (SPECT) showed hyperperfusion, more pronounced in the right frontal area. These findings are consistent with a hemimegalencephaly. Hemimegalencephaly with such a progressive expansion has never been described previously. These findings are consistent with a hemimegalencephaly showing progressive expansion, which has never been described previously.     

Hypoglycaemic hemiplegia: a repeat SPECT study.

During a hypoglycaemic right hemiplegia induced by a deliberate overdose of oral hypoglycaemics, brain CT and angiography revealed no abnormalities. SPECTs made one day and six days later showed relative hypoperfusion in the left hemisphere. Repeat SPECT study suggested that the left hemisphere was more vulnerable than the right in the cerebral blood perfusion. This vulnerability might provoke the right hemiplegia in a critical condition, such as severe hypoglycaemia.     

Long-term cognitive outcome of hemiconvulsion–hemiplegia–epilepsy syndrome affecting the left cerebral hemisphere

Long-term cognitive outcome following hemiconvulsion–hemiplegia–epilepsy (HHE) syndrome has been poorly studied, with little attention to the implications of side of involvement in HHE. This retrospective study describes language lateralization and cognitive performance in five patients with HHE syndrome affecting the left cerebral hemisphere. All of the patients had to have intracarotid sodium amytal testing (IAT) to be included in this study. The mean age of the patients was 30.2 years (range: 13–50). All patients had their hemiconvulsive seizures before age 1½ years (range: 6–13 months). All patients had right-sided hemiatrophy of the body, left mesial temporal sclerosis, and seizures originating from the left temporal lobe. The habitual seizures began at a mean age of 4.5 years (range: 1.5–12 years). Performance on tests of intelligence, verbal memory, and visual memory was examined. Language was represented in the right cerebral hemisphere in three patients, the left hemisphere in one patient, and both hemispheres with predominance on the right side in the fifth patient. Intellectual functioning was in the borderline to extremely low range among the patients with right hemispheric or bilateral representation for language. These patients were variably impaired on measures of verbal and visual memory. The patient with left hemispheric representation for language performed in the average range on tests of intellectual functioning and verbal memory, whereas scores on visual memory were variable. This study demonstrated that reorganization of language to the right cerebral hemisphere or its bilateral representation is common in patients with HHE syndrome affecting the left cerebral hemisphere, and is associated with poor cognitive outcome.     

A serial study of regional cerebral blood flow before and after hemispherectomy in a child

Hemimegalencephaly (HME) is a severe unilateral brain malformation the prognosis of which may be improved by hemispherectomy. HME also provides a unique opportunity to compare normal and pathological hemispheric function in the same patient. We performed a serial functional cerebral imaging study in a child suffering from a neuropathologically confirmed left HME. He was hemispherectomized at 11 months because of intractable epilepsy; this led to cessation of seizures and dramatic psychomotor improvement. Regional cerebral blood flow (rCBF) was studied at 1, 7, 10, 12 and 25 months with single photon computed tomography (SPECT) using 133-Xenon and with simultaneous EEG recording. At one month of age SPECT was performed ictally. During left EEG discharges, rCBF was 40% higher on the left hemisphere than on the right, even in occipital and frontal regions, usually immature at this age. A crossed cerebellar hyperperfusion was also found. At 7 and 10 months, SPECT was performed interictally; rCBF was 45% lower in the left hemisphere than in the right. During follow-up, global and regional CBF values showed normal levels and normal maturation in the right hemisphere except for a mild and transient decrease observed one month after hemispherectomy. SPECT provides an additional procedure for studying hemispheric function in vivo. Serial SPECT imaging may be useful for the preoperative and postoperative evaluation in unilateral cerebral malformation.     

Clinical and Radiological Difficulties to Detect Isolated MCA Dissection before Intravenous tPA Therapy

A 64-year-old woman was admitted to our hospital 48 minutes after sudden onset of dysphasia and right hemiplegia. Head computed tomography revealed small infarcts in the left putamen and 4-dimensional computed tomography angiography depicted high-degree stenosis in the left middle cerebral artery and delayed filling of the contrast media in the left middle cerebral artery territory. The patient underwent intravenous tissue plasminogen activator treatment. On day 5 of hospitalization, the patient underwent conventional cerebral angiography, revealing internal carotid artery to middle cerebral artery dissection. Fortunately, subarachnoid hemorrhage as an adverse effect did not occur, although iv-tPA was administered without detecting middle cerebral artery dissection.     

Lacunar infarction as an embolic complication of cardiac and arch angiography

BACKGROUND: Lacunar infarcts are small, deep cerebral infarcts resulting from occlusion of small, penetrating cerebral arteries. They are most commonly associated with hypertension. Cardiac sources of embolization are sometimes present in patients with lacunes, but direct proof of a causal relationship is lacking. This report attempts to support the contention that emboli can cause lacunar syndromes and lacunar infarction. CASE DESCRIPTIONS: We report two cases of pure motor hemiplegia, each of which developed while the patient was undergoing cardiac or aortic arch angiography. Neither patient had a history of previous transient ischemic attack or stroke. Initial computed tomography of the brain was normal in each. Repeat computed tomography in one confirmed a small, low-density lesion in the posterior limb of the internal capsule on the side appropriate to the patient's symptoms and remained normal in the second patient. CONCLUSIONS: These two cases offer evidence that the classic lacunar stroke syndrome of pure motor hemiplegia can occur on an embolic basis.     

Kernohan's notch phenomenon demonstrated by diffusion tensor imaging and transcranial magnetic stimulation

Kernohan's notch phenomenon is the ipsilateral hemiplegia caused by compression of the contralateral cerebral peduncle against the tentorial edge by a supratentorial mass. Diffusion tensor imaging (DTI) and transcranial magnetic stimulation (TMS) could be useful for exploring the state of the corticospinal tract (CST). This report attempts to demonstrate Kernohan's notch phenomenon in a patient with subdural haematoma by using DTI and TMS. One patient and six normal control subjects were recruited. The patient showed severe right hemiplegia even though the subdural haematoma was located in the right hemisphere. Brain CT at the time of onset showed right transtentorial herniation, and T2 weighted images at 6 weeks after onset showed a leucomalacic lesion on the left cerebral peduncle. DTI and TMS were performed at 6 weeks after onset. The fractional anisotrophy value of the left midbrain and medulla of the patient was found to be decreased in comparison with that of the control subjects. On fibre tractography for the CST, an interruption was observed in the left midbrain and medulla. The motor evoked potential obtained from the right hand muscle showed delayed latency, low amplitude and a higher excitatory threshold, thus indicating that the CST of the left hemisphere had been damaged. It seems that the CST had been damaged at the left midbrain, although subdural haematoma and transtentorial herniation had occurred in the right hemisphere in this patient. This report demonstrates Kernohan's notch phenomenon in this patient using DTI and TMS.     

Delayed onset massive oedema and deterioration in traumatic brain injury.

A 52-year-old man fell from standing and a computed tomography (CT) scan revealed traumatic intracerebral haematoma and subarachnoid haemorrhage in the temporal cortex. He was treated without surgery and discharged. On day 30 after the accident, he had no neurological deficit. On day 37 he complained of headache and urinary incontinence, and on day 39 he was hospitalized due to progressive neurological deterioration (reduced conciousness, dilated pupils, and left hemiplegia). A CT scan revealed a diffuse low-density in the right cerebral hemisphere with marked midline shift. Emergency decompressive craniectomy and right temporal lobectomy were performed. Angiography after surgery revealed moderate vasospasm in the right middle and anterior cerebral arteries. The patient remained severely disabled. Delayed onset neurological deterioration can be caused by brain oedema and vasospasm after traumatic brain injury, despite an intervening period of improvement.     

Alternating hemiplegia of childhood and a pathogenic variant of ATP1A3: a case report and pathophysiological considerations

We describe a case of a child suffering from alternating hemiplegia with a heterozygous p. E815K pathogenic variant of ATP1A3. The patient started to present abnormal eye movements in the first days of life, followed by the appearance at 2 months of dystonic episodes, and later on, by recurrent episodes of alternating hemiplegia more often on the right side. A severe epilepsy started at the age of 2 years with episodes of status epilepticus since the onset which frequently recurred, requiring admission to the intensive care unit. MRI showed bilateral mesial temporal sclerosis and a left‐sided ischaemic lesion. Interictal EEG showed bilateral abnormalities, whereas postictal EEG after status epilepticus showed overt slowing on the left side, suggesting a predominant involvement of ictal activity of the left hemisphere. We hypothesize that in our patient, the left hemisphere might have been more prominently affected by the pathogenetic abnormalities underlying alternating hemiplegia of childhood, rendering it more prone to early ischaemic lesions and recurrent unilateral status epilepticus. We speculate whether alternating hemiplegia of childhood shares some common pathophysiological mechanisms with familial hemiplegic migraine that may be associated with a pathogenic variant of ATP1A2.     

Hemiconvulsion-hemiplegia syndrome and primary human herpesvirus 7 infection

We report a case of hemiconvulsion-hemiplegia (HH) syndrome. An 18-month-old female infant had a hemiconvulsion followed by left hemiplegia. Magnetic resonance imaging immediately after the onset of hemiplegia showed high intensity in the right hemisphere in diffusion-weighted images (DWI), while T1- and T2-weighted images were normal. Single photon emission computed tomography showed hypoperfusion of the right hemisphere in the acute phase. Virological analyses proved primary human herpesvirus 7 (HHV-7) infection. DWI are useful for the early evaluation of HH syndrome. Vascular disorders due to HHV-7 infection may have been related to the development of HH syndrome in this patient.     

Unilateral persistent hyperhidrosis after ischemic stroke]

A 64-year-old right hemiplegic woman, who had been treated for hypertension for 15 years, was admitted to our hospital. Neurologic examination on admission disclosed right hemiplegia and motor aphasia; however, ophthalmoparesis, pupillary abnormality, and blepharoptosis were not evident. Excessive sweating on the right side of the body, which was most marked on the face, was observed. Amount of sweating on the left side of the body was normal. Unilateral hyperhidrosis persisted for more than 2 months. MRI revealed hemorrhagic infarctions in the left basal ganglia, internal capsule, thalamus, hypothalamus, and medial part of the cerebral peduncle. 123I-IMP SPECT disclosed hypoperfusion in the left striatum, thalamus, occipital cortex, and right cerebellar hemisphere. Cerebral angiography revealed arteriosclerotic changes in the basilar artery, but that the left posterior cerebral artery and its branches were not occluded. Unilateral persistent hyperhidrosis is rare after ischemic stroke. Hypothalamic lesion was thought to be responsible for the hyperhidrosis in this patient. As the hypothalamus receives its blood supply from the posterior cerebral artery, unilateral persistent hyperhidrosis may be an important sign of cerebral infarction in the posterior cerebral artery region.     

Simple Partial Status Epilepticus Localized by Single-Photon Emission Computed Tomography Subtraction in Chronic Cerebral Paragonimiasis

A patient with chronic cerebral paragonimiasis began to have new motor seizures of the right face manifested by clonic contractions that occurred several hundred times a day, consistent with simple partial status epilepticus. Ictal electroencephalogram discharges started from the left frontal region and then spread to the left hemisphere with left frontal maximum. But clinical seizures were limited to the right face. The frequent partial seizures were controlled by the intravenous infusion of phenytoin. Brain magnetic resonance imaging showed multiple conglomerated round nodules with encephalomalacia in the left temporal and occipital lobes. Applying the technique of ictal-interictal single-photo emission computed tomography subtraction, the authors were able to localize the focal ictal-hyperperfusion on left precentral cortex adjacent to the lesions that correspond to the anatomical distribution of left face motor area.     

Asymmetric arthrogryposis multiplex congenita with focal pachygyria

A male infant with predominantly right-sided arthrogryposis multiplex congenita is presented. His posture in the lower extremities was asymmetric, and left thoracic scoliosis was present. This patient also manifested focal pachygyria dominantly affecting the contralateral cerebral hemisphere and hypoplasia of the corpus callosum, brainstem, and cerebellar vermis. Generalized tonic seizures began at 2 months of age, and an electroencephalogram revealed epileptic discharge. Biopsy of the right biceps revealed a nonspecific change. A direct causal relationship between neuronal migration disorders and arthrogryposis multiplex congenita has not been established, but considering the abnormal neuronal migration along the entire neural axis in focal pachygyria, the predominantly right-sided arthrogryposis in this patient was speculated to be closely related to the pachygyria of the frontal and temporal lobes dominantly affected in the left cerebral hemisphere.     

Ictal 99mTc-HMPAO SPECT in alternating hemiplegia

99mTc-hexamethylpropylenamine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) was performed in a patient with alternating hemiplegia during 2 episodes of the disease. The regional cerebral blood flow patterns correlated with the clinical manifestations during both episodes. Hyperperfusion of the contralateral hemisphere was suggested by asymmetric 99mTc-HMPAO uptake, whereas symmetric 123I-N-isopropyl-p-iodoamphetamine uptake was detected during the interictal period. The results suggested that alternating hemiplegia in infants represents an atypical manifestation of epilepsy, despite the lack of paroxysmal electroencephalographic abnormalities during the episodes. 99mTc-HMPAO SPECT appears to be a useful method for detecting transient regional cerebral blood flow alterations during paroxysmal events because the tracer is rapidly available for emergencies and retains a fixed distribution for 5-8 hours, sufficient time to allow for SPECT acquisition.     

Aphasia following pluridirectional tomography with metrizamide. The effect of patient position

Eight of 67 patients became transiently aphasic after myelography or cisternography with metrizamide. All eight patients had been placed in the left lateral decubitus position for pluridirectional tomography. Immediate EEGs revealed focal left-sided abnormalities in two patients. In one other patient, a computed tomographic scan showed contrast mainly over the left hemisphere. All of the symptoms resolved within 48 hours. In 34 patients who were placed on the right side, no language disturbance was noted. Aphasia after pluridirectional tomography with metrizamide may be due to local irritation of the perisylvian language centers of the dominant hemisphere. The phenomenon is distinct from syndromes of generalized confusion. The complication may be avoided by placing patients in a right lateral decubitus position for pluridirectional tomography.     

Reversed laterality of cerebral functions in a non-right-hander: neuropsychological and spect findings in a case of 'atypical' dominance.

A 54-year-old non-right-handed man with positive familial sinistrality showed a pure right hemisphere syndrome following a left hemisphere stroke. Severe right side hemineglect, transcortical motor dysprosodia, spatial dysgraphia and visuo-constructive impairments were observed. At no time were the expected left hemisphere abnormalities such as aphasia, alexia, right-left disorientation or finger agnosia noted. A left fronto-temporal subcortical lesion was documented on CT scan. A Tc-99m HM-PAO SPECT study revealed no cerebral blood flow changes in the right hemisphere while in the left hemisphere a fronto-temporo-parietal cerebral blood flow reduction was evident. This case of a complete reversed laterality of cognitive functions argues for a distinction to be made between 'anomalous' cerebral dominance and 'atypical' cerebral dominance.     

Slowly progressive aphasia without generalized dementia: studies with positron emission tomography

Slowly progressive aphasia without generalized dementia is a degenerative syndrome selectively affecting dominant hemisphere language areas. We report changes in regional glucose metabolism measured by positron emission tomography in two patients with this condition. Striking abnormalities of glucose utilization in the left cerebral cortex were demonstrated in both patients. The findings of other neurodiagnostic studies were relatively unremarkable. The first patient had a 3-year history of progressive anomia and impaired auditory verbal recall. An electroencephalogram was normal, and computed tomography showed mild left perisylvian atrophy. Positron emission tomography revealed profound hypometabolism in the left temporal regions. The second patient also had a 3-year history of progressive anomia. Electroencephalography, computed tomography, and magnetic resonance imaging scans were normal. Positron emission tomography showed a major reduction in left parietal glucose utilization, with a lesser decrement in left temporal metabolism. Neither patient demonstrated significant contralateral or global abnormalities such as those reported in positron emission tomographic studies of Alzheimer's disease with or without focal clinical features. These observations support the concept of adult-onset progressive aphasia without dementia as a clinical syndrome distinct from Alzheimer's disease.     

Sequential 123I-IMP-SPECT in acute infantile hemiplegia

Sequential 123I-N-isopropyl-p-iodoamphetamine (IMP) single-photon emission computed tomography (SPECT) was performed in 2 patients with acute infantile hemiplegia. In both patients, low uptake of IMP was detected in the targeted abnormal hemisphere. The 123I-IMP-SPECT findings indicative of a pathologic condition persisted even when the clinical findings and electroencephalographic abnormalities improved. Because of its sensitivity, noninvasiveness, and accurate reflection of the cerebral blood flow distribution, 123I-IMP-SPECT is useful in the examination of acute infantile hemiplegia and in the evaluation of prognosis.