Imaging findings after methanol intoxication (cohort of 46 patients)

OBJECTIVES

Our goal is to demonstrate the variability of imaging findings, primarily in the MRI, in 46 patients who survived acute methanol poisoning. This cohort of patients is the largest such sample group examined by MRI.

METHODS

Patients were examined by means of imaging methods (42 patients by MRI and 4 by CT). All had an identical protocol of MR examination (T2WI, FLAIR, T1WI with or without application of contrast medium and T2WI/FFE, DWI in the transversal plane of the scan, and with focus on the optic nerves in the coronal plane of the scan in T2WI-SPIR).

RESULTS

Imaging methods revealed a positive finding associated with methanol intoxication in 21 patients (46%). These consisted of symmetrical lesions in the putamen--13 patients (28%), haemorrhage--13 cases (28%), deposits in white matter with localization primarily subcortically--4 cases (9%), lesions in the region of the globus pallidus--7 cases (15%) (in 6 cases without combination with the lesions in the putamen), lesions in the brainstem afflicted 6 patients (13%), and lesion in the cerebellum was found in one case. A pathological finding was found only in the patients examined by MRI.

CONCLUSION

Almost half of the patients who survived acute methanol poisoning had pathological findings by MRI. The most common finding concerned an affliction of the putamen, which is a predilection area. An interesting finding was the relatively frequent occurrence of selective lesion of the globus pallidus, which is more usually associated with other types of intoxication.

Methanol poisoning: characteristic MRI findings

Acute methanol intoxication is not an unusual poisoning. It can have serious neurological sequelae. We emphasize how neuroimaging can help in distinguishing methanol poisoning from other causes of acute unconsciousness in alcoholic patients such as hypoglycemic brain damage and carbon monoxide poisoning or head injury, which are frequently observed in alcoholic patients and are also responsible for altered sensorium. The most important findings in MR brain imaging in methanol poisoning have been bilateral putaminal hemorrhagic necrosis. Other less common findings are subcortical and deep white matter lesions, cerebral and cerebellar cortical lesions, and midbrain lesions, cerebral and intraventricular hemorrhage, and even enhancement of necrotic lesions, we found almost the entire spectrum of MRI findings in this patient with methanol poisoning. Neurological sequelae can entail the course and prognosis in methanol poisoning. The patient died because of ventilator-associated pneumonia that developed in the course of prolonged hospitalization.

Controversy in the management of lenticulostriate artery dissecting aneurysm: a case report and review of the literature

BACKGROUND

Intracranial arterial dissection is an uncommon but well-recognized entity. Treatment remains variable, ranging from observation to intervention via the use of either surgical or endovascular techniques. Aneurysms along the lenticulostriate artery have been reported in only 41 patients. With the current case study we illustrate the effectiveness of observation in the context of a dissecting lenticulostriate aneurysm and discuss other approaches that have been used in the treatment of this particular entity.

CLINICAL SUMMARY

An accomplished mountain climber presented, after coitus, with acute headache, mild facial weakness, and forgetfulness. Vascular imaging studies revealed a right putaminal hemorrhage secondary to a 3-mm lenticulostriate artery dissecting aneurysm. Clinically, the patient did well, with marked improvement in presenting symptoms enabling his return to mountain climbing. Follow-up angiography showed spontaneous resolution of the arterial dissecting aneurysm. Among the 41 reported cases, 19 were idiopathic, 5 associated with hypertension, and 17 related to various conditions such as Moyamoya disease, arteriovenous malformation, systemic vasculitis, intraventricular tumor, or substance abuse. Of the 42 cases, including the present case, 28 were surgically or endovascularly managed and 12 observed. Only one of the reported cases, a 33-year-old man with Moyamoya disease, who was managed conservatively, died of rebleeding.

CONCLUSION

There is no common consensus in the literature on a single treatment strategy for a lenticulostriate artery aneurysm. The present case illustrates that observation and follow-up vascular imaging can be an important treatment strategy, allowing healing of the vessel wall and disappearance of the dissecting aneurysm.

[Case of ruptured middle cerebral artery bifurcation aneurysm presenting as putaminal hemorrhage without subarachnoid hemorrhage]

Ruptured aneurysms typically present as subarachnoid hemorrhage (SAH); however, they can also cause intracerebral hemorrhage (ICH) that can be mistaken for hypertensive hemorrhage. We report a rare case of a ruptured middle cerebral artery bifurcation aneurysm presenting as putaminal hemorrhage without subarachnoid hemorrhage (SAH). A 47-year-old man, with a past history of hypertension, presented with a decreased level of consciousness. Neurological examination revealed hemiparesis of the right side. A CT scan on admission demonstrated left putaminal hemorrhage without SAH. Three-dimensional CT and conventional angiograms demonstrated a superiorly directing aneurysm of the M1/M2 portion of the left middle cerebral artery (MCA). We performed aneurysmal clipping and hematoma evacuation. The postoperative course was uneventful. This case suggested that ruptured aneurysms situated on the middle cerebral artery can present as putaminal hemorrhage without SAH.

Haemorrhagic presentation of low-grade glioma in adults

Intracranial bleeding is rare in patients with low-grade gliomas, above all in adult population. We reviewed the literature of such cases and reported another case of a haemorrhagic low-grade glioma in a 54-year-old woman presenting with a left hemiparesis. Computer tomography (CT) images showed a right basal ganglia haemorrhage with no mass effect. Vascular malformations were ruled out by angiography. Eighteen fluoro-fluoro deossiglucosio (18F-FDG) positron emission tomography (PET/CT) showed a large hypometabolic area corresponding to the lesion. We waited for patient's improvement. Late magnetic resonance images revealed a low-grade glioma at the bleeding site. Tumour was removed and histopathologic examination revealed a WHO grade II mixed glioma. The authors emphasize that this evidence has to be kept in mind since it has important therapeutic implications.

Angiographic examination of spontaneous putaminal hemorrhage

BACKGROUND

This study was carried out to examine indications for angiographic evaluation in the case of spontaneous putaminal hemorrhage.

METHODS

Angiographic examinations were performed on 62 consecutive adults with spontaneous putaminal hemorrhage without remarkable subarachnoid hemorrhage. Most patients were evaluated using conventional catheter angiography except for hypertensive patients over the age of 60 who underwent a magnetic resonance angiogram or a computed tomography angiogram. Computed tomography and clinical factors such as age and hypertension were correlated with the angiographic findings.

RESULTS

Nine of the 62 patients (15%) exhibited angiographic abnormalities, including middle cerebral artery aneurysm (n = 1), arteriovenous malformations (n = 3), moyamoya disease (n = 2), and the moyamoya phenomenon associated with a proximal middle cerebral artery occlusion (n = 3). The angiographic yield was significantly higher (1) among patients at or below the median age of 55 compared with those above (9/33, 27%, versus 0/29, 0%; p < 0.01), and (2) among patients without hypertension compared with those with hypertension (5/9, 56%, versus 4/53, 8%; p < 0.01).

CONCLUSIONS

Although our data could be biased due to the patient selection procedure, they suggest that angiographic evaluation is highly useful for spontaneous putaminal hemorrhage regardless of volume and shape of the hematomas, excepting hypertensive patients over 55 years of age.

[A case of postpartum cerebral angiopathy with intracranial hemorrhage and subarachnoid hemorrhage immediately after delivery]

A 32-year-old woman, gravida 0, para 0, was admitted for delivery at 40 weeks of gestation. She had no history of headache, hypertension, and toxemia. She was delivered of a healthy boy. Although she was given no medication during normal delivery, she suddenly became drowsy and developed left hemiparesis immediately after delivery. Computed tomographic (CT) scan of the brain performed on the admission day revealed a subarachnoid hemorrhage and right putaminal hemorrhage. A 4-vessel cerebral angiogram demonstrated multiple irregular narrowing of the anterior cerebral arteries, middle cerebral arteries, and posterior cerebral arteries. Her conditions seemed to improve without any medication, and the multiple stenoses were no longer observed by angiography in a follow-up examination. On the basis of these observations, she was diagnosed as having postpartum cerebral angiopathy (PCA). Pathogenesis of PCA still remaing unclear to date an ergot alkaloid derivate (ergonovine) and the hydrogenated form of the powerful vasoconstrictor ergot (bromocriptine) have been reported as cause of PCA. We will classify PCA into 3 categories: eclampsia, secondary PCA, and primary PCA. "Primary PCA" is of unknown etiology, "secondary PCA" results from a known etiology such as drugs, and "eclampsia" is a PCA with toxemia of pregnancy. We report here, that PCA may occur even in a normal pregnant woman who was given no medication, and should be considered in the diagnosis of postpartum cerebral vascular diseases in women.

[Putaminal hemorrhage in a case of Turner's syndrome with hyperaldosteronemia]

A case of Turner's syndrome complicated with intracerebral hemorrhage in a 21-year-old female is presented. The patient experienced acute onset of unconsciousness and the left-sided hemiparesis due to the right-sided putaminal hemorrhage. Severe hypertension was seen at the hospitalization. Cerebral angiography revealed no vascular lesion other than the displacement of lenticulostriate arteries. Emergent surgical evacuation of the hematoma was successfully performed with her favorable outcome. Postoperatively, several hormonal tests indicated hyperaldosteronemia secondary to the increased levels of ACTH and renin as a result of hyper-response to the environmental stress, leading to critical hypertension. Other examinations including CT scan, MRI, MRA, and laboratory data showed no abnormalities suggestive of renal lesions. It is supposed that hypertension, as a frequent presenting feature, should be strictly controlled in Turner's syndrome from the first time of diagnosis.

Bilateral putaminal hemorrhage with cerebral edema in hyperglycemic hyperosmolar syndrome

Bilateral putaminal hemorrhages rarely occur simultaneously in hypertensive patients. The association of intracerebral hemorrhage with cerebral edema (CE) has been rarely reported in diabetic patients. We present a patient with bilateral putaminal hemorrhage (BPH) and CE during the course of hyperglycemic hyperosmolar syndrome (HHS). A 40-year-old man with a history of diabetes mellitus and chronic alcoholism was admitted with acute impaired mentality. His blood pressure was within the normal range on admission. Laboratory results revealed hyperglycemia and severe metabolic acidosis without ketonuria. After aggressive treatment, plasma sugar fell to 217 mg/dl, but brain CT showed BPH and diffuse CE. Our case demonstrated that HHS should be considered as a cause of BPH with CE. Initial brain imaging study may be recommended for patients with diabetic coma.

August 2000: Two cases with necrosis and hemorrhage in the putamen and white matter

The August COM: Acute methanol poisoning is an uncommon, but well-recognized, cause of central nervous system injury. We present two autopsy cases showing the classic neuropathologic injuries in acute methanol poisoning: putamen and white matter necrosis and hemorrhage. In Case 1, putamen hemorrhages were striking; white matter pathology predominated in Case 2. The precise mechanism of methanol toxicity is unclear. Direct toxicity of metabolites, particularly formic acid, as well as ischemic injury and acidosis likely play a role. Methanol is readily available in many commercial products, and may be ingested accidentally or intentionally.

Simultaneous hypertensive intracerebral hematomas: two case reports

We describe two patients (76- and 54-year-old females) with multiple hypertensive intracerebral hematomas occurring simultaneously. One patient had a right thalamic hematoma extending into the internal capsule and basal ganglia together with an other one in the left putamen. The other patient had two hematomas located ipsilaterally in the left putamen and thalamus. Their neurological examinations showed only unilateral deficits. Their magnetic resonance angiograms revealed no vascular malformations. Neuroradiological procedures are essential for the diagnosis of these multiple brain events.