A case of herpes simplex encephalitis diagnosed by polymerase chain reaction]

A case of a 55-year-old male with herpes simplex encephalitis (HSE) was reported. He was admitted because of fever, headache and memory disturbance. T1 weighted MRI showed low signal intensity and T2 weighted imaging revealed high signal intensity in the medial portions of bilateral temporal lobes. Herpes simplex virus (HSV) antibody titer in cerebrospinal fluid (CSF) was not elevated. HSV DNA in CSF was amplified by polymerase chain reaction (PCR) and identified by the microplate hybridization method. The PCR technique would be useful for the diagnosis of HSE.     

A case of herpes simplex encephalitis with cerebral white matter lesion after acyclovir administration

Herpes simplex virus (HSV) is regarded as an agent that selectively affects temporal and frontal lobes with necrosis and hemorrhage, and no case of herpes simplex encephalitis (HSE) with white matter lesion in a diffuse fashion has previously been reported. A 2-year-old boy developed high fever, right hemi-convulsions and lethargy. Computed tomography (CT) showed wedge-shaped areas of high density in the left frontal region, whereas, cerebral angiography disclosed no vascular abnormality. T1-weighted magnetic resonance imaging (MRI) demonstrated cortical changes which were similar to those illustrated by CT. However, T2-weighted images depicted further spread high intensities of the lesion. The patient's symptoms spontaneously disappeared before an antiviral drug, acyclovir, was administered. After the significant increase of HSV antibody titers in serum and cerebro-spinal fluid (CSF) established a definite diagnosis, acyclovir was intravenously given at a daily dosage of 30 mg/kg for a period of 6 days in order to prevent the recurrence of HSE. Two months later, T2-weighted MRI visualized a diffuse lesion of increased signal intensities involving the white matter of both hemispheres, while both CSF protein and myelin basic protein were significantly elevated. Despite of these changes of the white matter, our patient developed a few symptoms such as mild speech disturbance, slight weakness of the right upper limb and sialorrhea. Although the mechanism of these changes in the white matter remains obscure, it is postulated that a direct invasion of HSV to the white matter, an immunological disorder following HSV infection and a side effect of acyclovir could have triggered a reversible process of demyelination of the cerebral white matter.     

Optochiasmal arachnoiditis following cotton wrapping of anterior communicating artery aneurysm treated by surgical removal of granuloma.

We report the case of a 50 year old female who presented with visual disturbance due to optochiasmal arachnoiditis and foreign body granuloma 9 months after cotton wrapping for ruptured anterior communicating artery (AcomA) aneurysm. Magnetic resonance imaging (MRI) revealed enhanced mass lesion around AcomA complex and hyperintense signal on optic chiasm and right optic tract by fluid-attenuated inversion recovery image. Despite the repeated steroid pulse therapy, she deteriorated and MRI showed expansion of the granulomatous lesion over 5 months. Surgical removal of foreign body granuloma resulted in marked improvement of visual disturbance as well as of the MRI findings. We conclude that the use of cotton sheet close to the optic nerve should be avoided, and that surgical removal of the granuloma would be the optimal choice especially for the patient in whom steroid therapy fails to improve clinical symptoms.     

Imaging and laboratory investigation in herpes simplex encephalitis

A 14 day old baby presented with signs of an acute encephalitis. Clinically, herpes simplex encephalitis (HSE) was suspected. Early MRI and EEG were normal and there was rapid clinical improvement. A negative polymerase chain reaction (PCR) result on the initial CSF sample seemed to make HSE most unlikely. This diagnosis was subsequently proved after demonstration of specific antibody production using immunoelectrophoresis of the CSF. The child had extensive damage to brain tissue. The need for sequential analysis of CSF in making or refuting this diagnosis is illustrated.     

Bilateral medial medullary infarction

We present a case of bilateral medial medullary infarction demonstrated by magnetic resonance imaging (MRI) and review 12 previously reported cases. We classify these 13 cases (including the present case) into two groups according to the extent of the ischemic region: type 1, the ischemic lesion developed from the medullary pyramid to the medial longitudinal fasciculus; type 2, the lesion was confined to the medullary pyramid.A 71 year old man presented with slight disturbance of consciousness, dysarthria, disturbance of leftward gaze, no gag reflex and tetraparesis. He developed nearly complete horizontal ophthalmoplegia. MRI revealed upper medial medullary infarction bilaterally that extended to the pontomedullary junction. We propose that the prognosis of type 2 bilateral medial medullary infarction is better than that of type 1. Furthermore, the prognosis of bilateral medial medullary infarction itself may be better than previously indicated.     

A case of sarcoid meningoencephalitis with an isolated supratentorial lesion]

A rare case of sarcoid meningoencephalitis with no systemic lesion is reported here. A 58-year old man was admitted experiencing dull headache and speech disturbance. He had never received a diagnosis of systemic sarcoidosis. On admission, neurological examination revealed dysarthria, a defect of the right-side visual field and accelerated right Achilles tendon reflex. A T2-weighted MRI showed a high-intensity signal in the white matter of the left parieto-occipital lobe surrounded by severe brain edema with a mass effect. The meninges around the lesion were enhanced by gadolinium, but no enhancement was observed in the basal portion. Angiotensin-converting enzyme (ACE) activities of cerebrospinal fluid (CSF) and serum were within normal range. The level of interleukin-6 in the CSF was slightly elevated. Chest X ray films and chest CT revealed no abnormal lesions. Whole body gallium scanning showed a hot region only in the intracranial lesion. A brain biopsy was performed. Histological examination revealed typical granuloma of sarcoidosis accompanied by microvasculitis and epithelioid cell granuloma without caseous necrosis. Oral administration of prednisolone improved all symptoms and MRI findings. These observations suggest that release of cytokines from macrophages and epithelioid cells, as well as disruption of the blood-brain barrier due to microvasculitis, are involved in the mechanism responsible for producing lesions of sarcoid meningoencephalitis.     

Encephalo-myelo-radiculitis with high HSV-1 antibody index of CSF

A rare case of encephalo-myelo- radiculitis with high herpes simplex virus type 1 (HSV-1) antibody index of CSF was reported. The case was a 43-year-old male. Double vision, cerebellar ataxia, Th4-12 truncal segmental total sensory disturbance and urinary retention were found, but those symptoms disappeared after 3 weeks of administration of acyclovir and prednisolone. Because the HSV-1 antibody index of the CSF increased significantly, the patient's disease was summarised to have been due to HSV-1, T1-intensified MRI revealed a low-intensity area in the Th5-8 region which coincided with the lesion causing the neurological symptoms, while T2-intensified MRI revealed scattered high intensity area in the cerebral hemisphere. MRI was thus useful for confirming the lesions.     

Glioblastoma Mimicking Herpes Simplex Encephalitis

We report a case of 70-year-old man with glioblastoma presenting as acute encephalitic illness. The patient exhibited sudden onset of cognitive impairment and headache for 2 days. Initial brain MRI showed left temporal lobe hyperintensity, and cerebrospinal fluid cytology revealed a mild pleocytosis. The patient had initially improved after medical treatment with a presumptive diagnosis of herpes simplex encephalitis (HSE). After 8 months, the patient complained of recurrent seizures. A follow-up brain MRI revealed marked increases in size and surrounding perilesional edema in the left temporal lesion on T2-weighted images and a new contrast-enhancing lesion on gadolinium-enhanced T1-weighted images. Stereotactic brain biopsy revealed a glioblastoma. The atypical encephalitic presentation of glioblastoma should be considered if definitive evidence for the diagnosis of HSE cannot be obtained.     

Murray valley encephalitis mimicking herpes simplex encephalitis.

We describe a patient with serologically proven Murray Valley encephalitis (MVE), whose presentation was clinically and radiologically characteristic of Herpes simplex encephalitis (HSE). The reports of MRI abnormalities in MVE, and the closely related Japanese Encephalitis and West Nile virusii are mostly of bilateral thalamic or grey matter involvement. The MRI scan findings in this case instead showed the typical temporal lobe changes of HSE. Our case report highlights that MVE can mimic HSE, both clinically and radiologically. Therefore it is important to collect an accurate and detailed travel history from patients where there is a risk of exposure to MVE virus. If suspected, antibody testing of serum and CSF, and CSF for MVE-RNA if available, should be undertaken. This case also highlights the potential under-diagnosis of Murray Valley encephalitis.     

Case of consciousness disturbance following a fever with spreading lesion over the bilateral splenia of the corpus callosum on MRI]

We report a 66-year-old man with spreading lesion over the bilateral splenia of the corpus callosum shown on MRI. On admission, unknown fever and myoclonus-like involuntary movement in the left forefinger and middle finger were observed. There were no remarkably abnormal data in the serum, the cerebrospinal fluid and electroencephalogram. However, T2-weighted MRI revealed the high signal spreading over the bilateral splenia of the corpus callosum, while enhanced effects were not observed by Gd contrast on T1-weighted MRI. Diffusion and FLAIR MRI also showed the high signals limited to the same part of the splenia bilaterally as on T2-weighted MRI, discriminating it from other lacunar lesions and old cerebral infarctions. Neurological features, which were considered to be directly associated with the fresh lesion, were impairment of verbal and visual memories. Near the time the therapies including high-dose steroid were given, the consciousness of the patient worsened rapidly on a day-to-day basis and disseminated intravascular coagulation syndrome (DIC) also occurred. By administering low-molecule heparin, consciousness disturbance and involuntary movements recovered completely. Following the improved symptoms, FLAIR MRI showed a reduced level of the signal seven months after the onset. A demyelinating disease over the bilateral splenia of the corpus callosum should be considered as the final diagnosis. Follow-up of the changes in this case is expected to provide a more accurate diagnosis.     

Growth hormone secreting adenoma with unusual extension: coexisting pituitary cyst and its clinical significance.

A 58 year old man showed acromegalic features. The serum growth hormone (GH) level was 7.3 ng/ml and SMC (somatomedin-C) 637 U/ml. Triple stimulation test showed abnormal response compatible with a GH secreting tumour. The conventional enhanced MRI revealed a less enhanced hemisphere-shaped lesion at the right corner of the sella turcica. In addition, dynamic MRI demonstrated an elongated lesion extending to the left beyond the midline. The patient underwent transsphenoidal surgery. Besides the soft and suckable tumour at the right corner, we entered into a small cavity loosely filled with the tumour, which was subsequently also removed. The operative finding corresponded to the lesion shown in dynamic MRI. Postoperative GH and SMC levels became 2.3 ng/ml and 326 U/ml respectively. Incidental pituitary cystic lesions in autopsied cases have been reported to be 6-33%. This case had a GH secreting adenoma with coexisting pituitary cyst. The coexisting pituitary cyst supposedly influenced the unusual shape and extension of the pituitary adenoma. Coexistence of such lesion should be kept in mind for microadenoma on neuroradiological evaluation and on intraoperative inspection surrounding the tumour.     

Leptomeningeal Dissemination of a Low-Grade Brainstem Glioma without Local Recurrence

It is rare for low-grade gliomas to disseminate to the leptomeninges. However, low-grade gliomas with dissemination to the leptomeninges have been occasionally reported in children, and have generally been associated with local recurrence. A 16-year-old boy sought evaluation for diplopia and gait disturbance. A brain magnetic resonance imaging (MRI) revealed pontine mass, which was proved to be fibrillary astrocytoma on biopsy, later. Radiation therapy (5400 cGy) was given and the patient's symptoms were improved. He was followed-up radiologically for brain lesion. Seven months after diagnosis he complained of back pain and gait disturbance. A brain MRI showed a newly-developed lesion at the left cerebellopontine angle without an interval change in the primary lesion. A spinal MRI demonstrated leptomeningeal dissemination of the entire spine. Radiation therapy (3750 cGy) to the spine, and adjuvant chemotherapy with a carboplatin plus vincristine regimen were administered. However, he had a progressive course with tumoral hemorrhage and expired 13 months after diagnosis. We report an unusual case of a low-grade brainstem glioma with spinal dissemination, but without local recurrence, and a progressive course associated with hemorrhage.     

Isolated reversible splenial lesion in tick-borne encephalitis: a case report and literature review

Here, we demonstrate a first case of tick-borne encephalitis (TBE) associated with an isolated reversible splenial corpus callosum lesion (IRSL) and highlight the wide range of different clinical entities in which such alterations have been observed. A 42-year-old man showed fever, cephalgia and mild disturbance of coordination and gait. Diagnosis was ascertained by slight CSF-pleiocytosis and positive TBE-IgG as well as by positive intrathekal specific antibody index on follow-up. MRI demonstrated a single ovoid hyperintensity in T2 and DWI with reduction in ADC in the splenium of corpus callosum which was abrogated in follow-up after 6 weeks. Most entities of IRSL presented with excellent prognosis, including our novel case of TBE. We discuss different possible pathomechanisms and the so far unexplained propensity of the splenium for such alterations. Clinicians should be familiar with this phenomenon to avoid unnecessary diagnostic or therapeutic efforts.     

Fulminant leptomeningeal carcinomatosis from a malignant melanoma arising in a cerebellopontine epidermoid cyst: A rare case with diagnostic pointers

A malignant component in an epidermoid cyst is rare. We report an exceptionally rare case of a malignant melanoma arising in an epidermoid cyst located in the cerebellopontine (CP) angle. A 26‐year‐old woman presented with headache, vomiting, ataxia and difficulty in swallowing over the previous 3 months. The radiological finding suggested an epidermoid cyst and the lesion was excised. The histopathology confirmed a CP angle epidermoid cyst. Within 1 month of discharge, she developed hydrocephalus for which a ventriculo‐peritoneal shunt was performed. Postoperatively she developed weakness in lower limbs. A contrast‐enhanced MRI was done which showed dilated CSF cisternal spaces with a small enhancing lesion in the pineal region and enhancement of meninges extending to the spinal cord. Re‐exploration showed gelatinous material with gross adhesions in the CP angle cistern. A dural biopsy was done which showed sheets of poorly differentiated tumor cells which expressed S100 and Melan A and were immunoreactive with Human Melanoma Black (HMB)‐45 antibody, consistent with the diagnosis of malignant melanoma. Histology of the excised epidermoid cyst was re‐evaluated in deeper sections and showed scattered atypical melanocytes in the basal layer of the epidermis which were highlighted with HMB‐45 antibody. The patient expired within 3 days of the second procedure due to respiratory failure. A very aggressive fulminant course of the disease was evident after surgery for the epidermoid cyst. Treatment options are limited. Criteria for identification of malignancy in an intracranial epidermoid cyst were identified in our case retrospectively and have been highlighted.     

A case of meningoencephalitis caused by persistent Epstein-Barr (E-B) virus infection

A 44-year-old man had several episodes of tingling sensation in his lower extremities, head and face over 1 year and presented mental disturbance 2 months prior to admission. He additionally suffered from dysuria and acute onset of gait disturbance 18 days before admission. Physical and neurological examination revealed marked splenomegaly, stupor, abnormal behavior, spastic tetraparesis and sphincter disturbances, and meningoencephalitis was suspected. There was lymphocytosis in peripheral blood, some of which showed atypical morphology. CSF examination revealed increased protein content and mononuclear pleocytosis. The titers of antibodies against E-B virus were elevated as follows; VCA IgM (X320), VCA IgG (X20,480), EA (X10,240) and EBNA (X10) in serum, and VCA IgM (X4), VCA IgG (X160), EA (X40) and EBNA (less than 1) in CSF. CT and MRI examination revealed ring enhanced lesion adjacent to left lateral ventricle with surrounding diffuse edema. Administration of intravenous glycerol and oral prednisolone induced substantial improvement in sensory, mental and sphincter disturbances and brain CT findings but not in splenomegaly and pyramidal tract signs. Antibody titer against VCA IgM also decreased. After withdrawal of prednisolone, CSF and CT findings worsened, and the antibody titer became elevated again, and CSF and CT findings improved by readministration of prednisolone. From the above signs and laboratory data, especially continuous elevation of antibody titer against E-B VCA IgM for as long as 1 year, this case was considered to be a meningoencephalitis caused by persistent E-B virus infection.     

Hypogeusia in a 9-year-old girl with multiple sclerosis

We reported a case of hypogeusia in a 9-year-old girl with multiple sclerosis (MS). She had two episodes of neurological disturbances resembling those associated with MS, and diagnosed by McDonald's criteria. She complained of gustatory disturbance on the first attack. A quantitative test with four fundamental tastes (measurements with a filter paper disc) suggested decreased gustatory sensitivity in the right anterior part of the tongue. Magnetic resonance imaging (MRI) revealed a right thalamic lesion involving the ventral posteromedial nucleus parvocellular part (VPMpc). The patient was successfully treated with steroid pulse therapy, and improvement of neurological abnormalities involving gustatory disturbances was seen. Some studies of monkeys have demonstrated that the secondary neurons in the gustatory part of the solitary nucleus project ipsilaterally to VPMpc in the brainstem. The gustatory pathway in humans has not yet been demonstrated, but is speculated to be present based on that of monkeys. In the present case, we considered that the thalamic lesion involving VPMpc caused a decreased sense of taste in the ipsilateral part of the tongue. Several neurological abnormalities caused by multifocal demyelinating lesions can be observed in MS, but gustatory disturbance is rare. We quantitatively investigated unilateral gustatory disturbance in our patient, and concluded that the ipsilateral thalamic lesion detected by MRI could be causative.     

Acute encephalopathy with biphasic seizures and late reduced diffusion with visual disturbance and higher brain dysfunction

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a recently described clinicoradiologic syndrome. Clinically, a prolonged febrile seizure is followed by subsequent seizures which occur several days after the initial seizure. On MRI, reduced diffusion appears predominantly in the frontoparietal subcortical white matter at the time of the subsequent seizures. The main symptom between the initial and subsequent seizures is disturbance of consciousness. We report a case with AESD who presented 1) reduced diffusion on MRI which was dominant in the occipital lobe, and 2) reversible visual disturbance followed by higher brain dysfunction such as a cognitive deficit and disturbed speech. A 2-year-old Japanese girl was admitted because of visual disturbance which appeared 4 days after a generalized tonic-clonic seizure associated with fever. Two days later, she had another seizure when MRI revealed reduced diffusion in the subcortical white matter. The MRI finding was not typical of AESD in that reduced diffusion appeared dominantly in the occipital lobe. Normal ophthalmologic findings and abnormal visual evoked potential results suggested that her visual disturbance was due to an impaired visual pathway in the subcortical white matter in the occipital lobe. The present case indicates that there is a subgroup of AESD in which the subcortical lesion seen on MRI is dominant in the occipital lobe.     

Lung carcinoma metastasis presenting as a pineal region tumor

An autopsy case is reported of pineal metastasis from lung adenocarcinoma, which is a rare manifestation of the disease. A 75‐year‐old man who had been found to have a lesion in the lung by chest CT 2 years previously, became aware of head heaviness and then suffered consciousness disturbance. Brain MRI revealed a solitary mass in the pineal region with hydrocephalus. At autopsy a midsagittal section of the brain disclosed a well‐circumscribed mass consisting of epithelial cells occupying the third ventricle. Although it should be recognized that such metastasis is very rare, the present case provides further information that might be useful for diagnosis.     

Frontal pseudo-tumoral form of adrenoleukodystrophy

A case of adrenoleukodystrophy in a 9-year old boy revealed by a predominant frontal syndrome is reported. Brain MRI showed an unusual pseudo-tumoral frontal lesion. The diagnosis was confirmed by increased plasma levels of very long chain fatty acids. His young brother had an isolated adrenal insufficiency with normal brain MRI. The frontal predominance of the lesion and the clinical polymorphism of the disease in this family are discussed.     

Gadolinium-MRI findings of two adrenoleukodystrophy cases treated with gamma-globulin]

Two cases of adrenoleukodystrophy were reported. We treated them with intravenous gamma-globulin infusion. MRI with gadolinium enhancement was performed before and after the therapy to evaluate the effect of gamma-globulin. Case 1 was a 19-year-old boy, who noticed left hemianopsia when he was 18 years old. Case 2 was a 36-year-old man, who developed ataxic gait and character change when he was 33 years old. Very long chain fatty acids in plasma and RBC membrane were elevated in both cases. On T2-weighted image of MRI, high signal lesions were seen in the white matter of occipital lobe in case 1, cerebellum, internal capsule, and around the corpus callosum in case 2. On T1-weighted image, the rim of every lesion was enhanced by gadolinium infusion. After the gamma-globulin therapy, gadolinium enhancement of the rim remarkably reduced in case 1. No reduction was observed in case 2. MRI findings of case 1 indicate the possibility that gamma-globulin may suppress the inflammation of the adrenoleukodystrophy.