Punch-drunk syndrome (PDS) refers to a pathological condition in which higher brain dysfunction occurs in a delayed fashion in boxers who have suffered repeated blows to the head. However, the underlying mechanisms remain unknown. This study attempted to elucidate the mechanism of higher brain dysfunction observed following skull vibration in two experiments involving a rat model of PDS. Experiment 1 evaluated the effects of edaravone on histological changes in the rat brain tissue after skull vibration (frequency 20 Hz, amplitude 4 mm, duration 60 minutes). The amount of free radicals formed in response to skull vibration was very small, and edaravone administration reduced the number of glial fibrillary acidic protein and advanced glycation end product-positive cells. Experiment 2 examined the time course of change in learning ability following skull vibration in Tokai High Avoider rats. The learning ability of individual rats was evaluated by the Sidman-type electric shock avoidance test 5 days after the last session of skull vibration or final anesthesia and once a month for 9 consecutive months. Delayed learning disability was not observed in rats administered edaravone immediately after skull vibration. These results suggest that free radical-induced astrocyte activation and subsequent glial scar formation contribute to the occurrence of delayed learning disabilities. Edaravone administration after skull vibration suppressed glial scar formation, thereby inhibiting the occurrence of delayed learning disabilities.
Motor cortex stimulation (MCS) has now become the preferred option for neurosurgical management of intractable central neuropathic pain such as post-stroke pain and trigeminal neuropathic pain. However, the efficacy of MCS for other central neuropathic pain such as pain resulting from spinal cord or brainstem lesions is unclear. We retrospectively reviewed 11 consecutive patients with intractable central neuropathic pain who underwent MCS in our institution. Eight patients had poststroke pain caused by thalamic hemorrhage (n = 5) or infarction (n = 3) (thalamic group). Two patients had postoperative neuropathic pain caused by spinal cord lesions, and one patient had facial pain caused by a brainstem lesion associated with multiple sclerosis (brainstem-spinal group). Visual analog scale and stimulation parameters were evaluated at 1 and 6 months postoperatively. MCS was effective for six of eight patients in the thalamic group, and all three patients in the brainstem-spinal group. These efficacies continued for 6 months after surgery without significant change in the stimulation parameters compared with the parameters at 1 month in both groups. The mean amplitude at 1 month and frequency at 6 months after surgery were significantly higher in the brainstem-spinal group than the thalamic group, although the patient number was small. MCS is effective for other central neuropathic pain, but higher intensity stimulation parameters may be necessary to gain adequate pain reduction.
The feasibility and reliability of combined use of transcranial and direct cortical motor evoked potential (MEP) monitoring during unruptured aneurysm surgery were evaluated. Forty-eight patients with unruptured cerebral aneurysms underwent craniotomy and neck clipping accompanied by muscle MEP monitoring. MEPs were elicited successfully by transcranial electrical stimulation in all patients. Direct cortical stimulation elicited MEPs in 44 patients. Reduction in MEP amplitude to less than 50% of baseline was considered significant. No postoperative motor paresis occurred in 39 patients in whom transcranial and direct MEPs remained unchanged. Four patients in whom direct MEPs could not be recorded had no intraoperative abnormality in transcranial MEPs and no postoperative motor dysfunction. Four of the other 5 patients manifested significant transient direct MEP changes without transcranial MEP changes. The transient MEP changes were observed in 3 patients during temporary clipping of the parent artery and in one patient with inadequate clipping of an middle cerebral artery aneurysm, and were considered due to insufficiency of blood flow. Decrease or disappearance of direct MEP waves recovered immediately after re-application of the clip and release of the temporary clip. Direct MEP waves disappeared and did not recover until the end of microsurgical procedures in one patient, although transcranial MEP amplitude remained at less than 50% of baseline. She developed hemiparesis postoperatively, which recovered within 6 hours. The duration of temporary occlusion in patients with direct MEP changes was significantly longer than that in patients without (p < 0.05). Direct MEP was sensitive in detecting ischemic stress to descending motor pathways during aneurysm surgery. Transcranial MEPs could be elicited in patients in whom direct MEPs could not be obtained, and during periods such as craniotomy or after dural closure, in which direct MEPs could not be recorded. These findings suggest that combined transcranial and direct cortical MEP recording may improve the feasibility and reliability of MEP monitoring during unruptured aneurysm surgery.
The International Subarachnoid Aneurysm Trial has shown that coil embolization achieves a better outcome for aneurysms treatable by either clipping or coil embolization. However, many ruptured aneurysms are hardly treatable by either clipping or coil embolization. Selection of either clipping or coil embolization will affect the treatment outcome for ruptured aneurysms. The relationship between patient selection and treatment outcome in a so-called “regional center hospital” in Japan must be clarified. This study included 113 patients with ruptured intracranial saccular aneurysms measuring less than 10 mm. Selection criteria for coil embolization were principally paraclinoid or posterior circulation aneurysm, Hunt and Hess grade IV or over, and patient age 75 years or older. Other aneurysms were principally treated by clipping. Aneurysms with a dome/neck ratio of less than 1.5, distorted aneurysms, Hunt and Hess grades I-III, patient age 74 years or younger, and middle cerebral artery aneurysm were actively treated by clipping. A few exceptional indications were considered in detail. Low invasiveness coil embolization is better than clipping to obtain good neurological outcome for patients with perforators difficult to dissect, aneurysms difficult to dissect due to previous open surgery, and aneurysms requiring bilateral open surgery, despite the slightly higher rebleeding rate in coil embolization. Overall outcomes were modified Rankin Scale (mRS) 0-2 in 82 of 113 patients (73%) and mRS 3-6 in 31 (27%). Appropriate selection of clipping or coil embolization can achieve acceptable treatment outcomes for ruptured aneurysm.
Patients with non-traumatic, non-aneurysmal, and non-perimesencephalic subarachnoid hemorrhage (SAH) tend to have clots circumscribed along the cortical convexity, a condition referred to as acute cortical SAH. Cerebral venous thrombosis (CVT) is a potential cause of cortical SAH. The study tried to establish the diagnosis and management of cortical SAH caused by CVT. Retrospective review of 145 patients with non-traumatic SAH identified 15 patients with no ruptured aneurysm. Clinical features were investigated with a specific focus on patients with SAH caused by CVT. Eight of the 15 patients had perimesencephalic SAH, and 7 had cortical SAH. SAH caused by CVT was diagnosed in 4 of the 7 patients with cortical SAH. The cortical SAH involved the unilateral convexity or sylvian cistern and spared the basal cistern on computed tomography in all 4 patients. CVT occurred in the transverse sinus and cortical vein (1 patient), insular vein (1 patient), and cortical vein (2 patients). Identification of thrombosed veins or sinuses was established directly by T2*-weighted and diffusion-weighted magnetic resonance (MR) imaging in the acute stage and diffusion-weighted and T1-weighted MR imaging in the subacute stage. All patients had cortical swelling without findings of venous hemorrhagic infarction on T2*-weighted MR imaging. None of the 4 patients received active treatment, and all had favorable outcomes. CVT in patients with non-traumatic cortical SAH should be first excluded as a potential hemorrhagic cause by MR imaging for thrombosed veins or sinuses before initiating antifibrinolytic therapy.
A 30-year-old woman presented with traumatic carotid-cavernous fistula associated with persistent primitive trigeminal artery (PPTA) manifesting as right conjunctival chemosis, exophthalmos, and diplopia. The lesion was treated successfully by trans-arterial coil embolization using the double catheter method with balloon assist. Injury to the PPTA is relatively rare and the PPTA should be sacrificed together with the fistula during the repair.
A 77-year-old man presented with an extremely rare association of anterior cranial fossa dural arteriovenous fistula (AVF) with anterior communicating artery (ACoA) aneurysm manifesting as consciousness deterioration due to intracerebral hemorrhage in the left frontal lobe and diffuse subarachnoid hemorrhage. Angiography confirmed the association of a dural AVF fed by both ethmoidal arteries and an ACoA aneurysm. Surgery for these two lesions was performed concurrently, and the ACoA aneurysm was found to be responsible for the hemorrhage. This association seems incidental, but is clinically significant since the preoperative determination of the bleeding point is difficult. We conclude that these two lesions should be treated simultaneously, to avoid leaving the ruptured point untreated.
A 68-year-old man presented with an extremely rare extracranial arteriovenous fistula (AVF) involving the inferior petroclival vein (IPCV) with retrograde venous drainage into an ophthalmic vein through the anterior condylar confluence and inferior petrosal sinus manifesting as ocular symptoms. The AVF was successfully treated by selective transvenous embolization with platinum coils. AVF involving the IPCV should be recognized as a possible extracranial lesion manifesting as clinical symptoms similar to cavernous sinus dural AVF.
A 50-year-old man presented with pituitary apoplexy resulting in internal carotid artery occlusion manifesting as sudden onset of severe headache, right ptosis, and left hemiparesis, associated with visual impairment. Computed tomography showed a nodular mass, located in the sellar and suprasellar regions with early signs of acute cerebral ischemia. Magnetic resonance (MR) imaging indicated that the mass compressed the bilateral cavernous sinuses, resulting in obliteration of the cavernous portion of the right internal carotid artery. Right middle cerebral artery territory infarction was also found. Conservative therapy with steroids was given in the acute stage and repeated MR imaging showed recanalization of the internal carotid artery with reduction of the tumor size. The tumor was removed through the transsphenoidal approach to obtain a definitive diagnosis in the chronic stage. The histological diagnosis was consistent with non-functioning pituitary adenoma. Eye movement of this patient showed full recovery after the operation. Pituitary apoplexy resulting in internal carotid artery occlusion is rare. Surgical decompression through the transsphenoidal approach is appropriate, but the optimal timing should consider severe disturbance of visual acuity and visual field in the acute stage.
An 80-year-old male presented with a chronic encapsulated intracerebral hematoma (CEIH) with surrounding edema under the right frontal lobe manifesting as slow exacerbation of disturbance of orientation and gait. He had a history of cerebral infarction with an asymptomatic cavernous angioma in the right frontal lobe. The CEIH was diagnosed as bleeding from the cavernous angioma, and surgical removal was performed. The hematoma was chronic and covered by a thick capsule. In addition, mass tissue covered with the organized hematoma was found near the capsule, which was excised and found to be a cavernous angioma. CEIH is a special type of intracerebral hemorrhage, and bleeding from a cavernous angioma is occasionally seen. CEIH should be considered in the case of a hemorrhagic intracranial lesion with a chronic, progressive course with capsule formation and edema around the lesion. The source of bleeding is unknown in about half of the reported cases, and occult vascular malformation may be involved, necessitating care in diagnosis.
A 60-year-old man presented with a rare case of primary angiitis of the central nervous system mimicking a tumor-like lesion and manifesting as slight disorientation, left hemiparesis, and motor aphasia. Computed tomography showed multiple low density lesions in the left frontal lobe, brain stem, and right parietal lobe. Magnetic resonance images revealed a slightly enhanced mass lesion in the right parietal lobe with surrounding brain edema. Serum, cerebrospinal fluid, and other image examinations did not show any abnormal findings, so surgical removal of the right parietal mass was performed. Histological examination revealed that the mass consisted of hemorrhagic infarction without cellular atypia. Proliferations of endothelial cells in small and medium arteries, and infiltration of macrophages in the perivascular space were detected in the infarction tissues. The histological diagnosis was primary angiitis of the central nervous system.
A 23-year-old male with non-communicating hydrocephalus caused by intraventricular hemorrhage from an arteriovenous malformation was treated by endoscopic third ventriculostomy (ETV) after repeated ventricular cerebrospinal fluid drainage and removal of ventriculoperitoneal shunt due to infection. Postoperatively, the patient developed robust rigidity and akinesia with mutism, suggesting secondary parkinsonism. These symptoms showed marked improvement after administration of levodopa, and were not aggravated after discontinuation. The pathophysiology of this case might involve dysfunction of the dopaminergic system caused by repeated compression and release of the paraventricular white matter. Careful perioperative management not leading to excessive dilation of the the ventricles should be considered for ETV for non-communicating hydrocephalus to avoid this unexpected complication.
A 44-year-old man presented with a very rare case of skull base osteomyelitis manifesting as persistent diplopia. He initially had the symptom with fever after dental extraction. Biopsy from the cervix and upper pharynx performed in a previous hospital had showed negative findings by histological and bacterial examinations. Magnetic resonance (MR) imaging disclosed enhanced lesions in the right cavernous sinus, clivus, and right cervical regions. Computed tomography revealed osteolysis, and fluorodeoxyglucose positron emission tomography (FDG-PET) showed areas of increased uptake. Bacteriological examination of the isolated clival lesion disclosed Actinomyces israelii, and he was treated with intravenous penicillin, 18 million units a day for 6 weeks. MR imaging revealed reduction of intensity in the enhanced areas, and FDG-PET showed disappearance of the increased uptake. After 6 months of oral antibiotics administration, MR imaging disclosed disappearance of the enhanced lesions, and the patient had no sign of neurological deficits. Skull base osteomyelitis resembles neoplasm or inflammatory disease of this region in neurological and radiographic findings. The biopsy specimen should be ideally obtained from an isolated region, and prepared to identify a wide range of organisms and to differentiate other diseases. The serum level of C-reactive protein and FDG-PET are useful to follow up the efficacy of antibiotic therapy.
Two patients presented with sciatica-like pain caused by thoracic disk herniation. Sciatica-like pain was the initial and major symptom in both patients, but careful neurological examination showed vague signs of upper motor neuron disturbance, and thoracic magnetic resonance (MR) imaging revealed disk herniations at the mid-thoracic level. After video-assisted thoracoscopic discectomy, the pain was completely improved. Thorough neurological examination and MR imagery of the thoracic spine, and if needed, even the cervical spine, are required if lumbar image findings do not correlate with the symptoms or physical examination.
A 58-year-old woman with refractory hypertension presented with subarachnoid hemorrhage. Digital subtraction angiography and three-dimensional computed tomography (CT) angiography revealed a ruptured left vertebral artery (VA) aneurysm and an unruptured left middle cerebral artery (MCA) aneurysm. The patient successfully underwent neck clipping of the left VA aneurysm. However, CT obtained just after the operation showed an asymptomatic cerebral infarction along the distribution of medial striate arteries of the right anterior cerebral artery in the caudate nucleus. The pathogenesis of the infarction was unknown. Before clipping surgery of the left MCA aneurysm, detailed examinations to find the cause of her refractory hypertension were performed. Laboratory tests revealed plasma serum level of norepinephrine at 15,521 pg/ml (normal range 100-450 pg/ml). Abdominal magnetic resonance imaging revealed a pheochromocytoma in the right adrenal gland. After preoperative management of the pheochromocytoma, the neck of the left MCA aneurysm was successfully clipped. When the patient awakened from anesthesia, she noticed right hemiparesis and motor aphasia. CT showed cerebral infarction along the distribution of lenticulostriate arteries of the left MCA in the putamen. Her symptoms gradually improved, and the pheochromocytoma was removed by laparoscopic surgery. Sustained severe hypertension and depletion of blood volume resulting from excess catecholamine release from the pheochromocytoma may have caused the complications. Hypervolemic fluid infusion and maintenance of normotensive blood pressure during surgery may avoid such ischemic events.
A 63-year-old man presented with headache. Magnetic resonance imaging showed a mass lesion homogeneously enhanced with gadolinium, which occluded the route from the third ventricle to the aqueduct. The patient underwent surgery for removal of the tumor via the right frontal transcortical-transventricular approach to the third ventricle via the transchoroidal route. Intraoperative diagnosis was meningioma. Total removal of the tumor was achieved in piecemeal fashion (Simpson grade 1). The histological diagnosis was meningothelial meningioma. The patient was discharged without neurological deficits. Third ventricle is a rare and difficult site to remove tumor totally. However, total removal was needed in this case of benign meningioma, so the operative strategy and the differential diagnosis before operation is considered to be very important.
A 60-year-old man presented with a rare cerebellar inflammatory myofibroblastic tumor (IMT) manifesting as gait disturbance and dysarthria. Brain magnetic resonance imaging demonstrated an intra-axial round-shaped isointense mass homogeneously enhanced with gadolinium in the right cerebellar hemisphere, as well as perifocal edema extending to the brain stem and right thalamus. The tumor was elastic hard and was resected en bloc with a clear margin. Histological examination revealed IMT with spindle cells and collagen, but negative for anaplastic lymphoma kinase expression. IMT most commonly affects the lung, but may involve many other parts of the body. There is some debate regarding the disease entity of IMT in the central nervous system (IMT-CNS) because of its rarity and high frequency of recurrence. IMT-CNS is an important differential diagnosis among tumor-like intracranial lesions and total resection is required.
A 20-year-old woman presented with subarachnoid hemorrhage (SAH) in the frontal interhemispheric fissure, and a cystic lesion in the left frontal lobe. Cerebral angiography demonstrated no aneurysm or vascular abnormalities. T1-weighted magnetic resonance imaging with contrast medium revealed an enhanced lesion along the falx. The lesion and cyst were removed, and histological examination revealed a pilocytic astrocytoma. Spontaneous intracranial hemorrhage from pilocytic astrocytoma is rare, with only 15 reported cases mostly involving intratumoral hemorrhage in the parenchyma of hypothalamic and cerebellar tumors. SAH caused by cerebral hemisphere pilocytic astrocytoma is extremely rare. This case suggests that interhemispheric fissure SAH, not associated with aneurysm or abnormal vascularity, could originate from small, low-grade glioma in the superficial cerebral hemisphere.
Intracranial epidermoid cysts generally appear as hypodense on computed tomography (CT), hypointense on T1-weighted magnetic resonance (MR) imaging, and hyperintense on diffusion-weighted MR imaging. We report two cases of posterior fossa epidermoid cysts with unusual radiological features. A 49-year-old male presented with facial dysesthesia and a 12-year-old male presented with diplopia and internuclear ophthalmoplegia. CT of both cases revealed hyperdense lesions. MR imaging showed the first case as hypointense in the posterior part and hyperintense in the anterior part of the tumor on diffusion-weighted imaging, and the second case as hyperintense on diffusion-weighted and T1-weighted MR imaging. Surgical exploration revealed that the tumors consisted of creamy materials, instead of the usual semi-solid or flaky texture in epidermoid cysts. Xanthochromic serous fluid was also contained in the superoposterior half of the cyst of the first case. These unusual contents of the cyst may be responsible for the unusual neuroimaging findings. Histological examination showed both cysts were lined with stratified squamous epithelium and contained keratinaceous materials. Therefore, epidermoid cysts can occasionally present with unusual radiological characteristics giving rise to a diagnostic pitfall.
The reluctance to incise skin with electrocautery is partly attributable to concerns about excessive scarring and poor wound healing. However, recently no difference was reported in wound complications between the cold scalpel and electrocautery scalpel. We assessed the safety and efficacy of electrocautery skin incision in 22 scalp incisions, including 4 cases of reoperation. Electrocautery skin incisions were created using a sharp needle electrode. The generator unit was set on cutting mode, with power of 6 W and 330 kHz sinusoid waveform. Subcutaneous dissections also used the sharp needle electrode, set on coagulating mode, with power of 10 W and 1 MHz pulse-modulated waveform. Galea incisions used a standard blade tip, set on coagulating mode, with power of 20 W and 1 MHz pulse-modulated waveform. Skin incision with the sharp needle electrode caused no charring of the wound. Little bleeding or oozing were observed and skin clips were not necessary. No wound complication such as necrosis or infection occurred. Electrocautery skin incisions for re-operations were also performed safely without complications. Electrocautery skin incision is sufficiently safe procedure not only for first operation but also for re-operation. Electrocautery skin incision is efficacious, especially for extended operation times, because of little blood loss from the edges of skin incision and possible avoidance of skin edge necrosis or alopecia caused by skin clips.