Neuroradiologic Diagnosis of Minor Leak prior to Major SAH: Diagnosis by T1-FLAIR Mismatch.

BACKGROUND AND PURPOSE: In major SAH, the only method to diagnose a preceding minor leak is to ascertain the presence of a warning headache by interview; however, poor clinical condition and recall bias can cause inaccuracy. We devised a neuroradiologic method to diagnose previous minor leak in patients with SAH and attempted to determine whether warning (sentinel) headaches were associated with minor leaks before major SAH. MATERIALS AND METHODS: We retrospectively evaluated 127 patients who were admitted with SAH within 48 hours of ictus. Previous minor leak before major SAH was defined as T1WI-detected clearly bright hyperintense subarachnoid blood accompanied by SAH blood on FLAIR images that was distributed over a larger area than bright hyperintense subarachnoid blood on T1WI (T1-FLAIR mismatch). RESULTS: The incidence of warning headache before SAH was 11.0% (14 of 127 patients, determined by interview). The incidence of T1-FLAIR mismatch (neuroradiologic diagnosis of minor leak before major SAH) was 33.9% (43 of 127 patients). Of the 14 patients with warning headache, 13 had a minor leak diagnosed by T1-FLAIR mismatch at the time of admission. Variables identified by multivariate analysis as significantly associated with minor leak diagnosed by T1-FLAIR mismatch included 80 years of age or older, rebleeding after admission, intracerebral hemorrhage on CT, and mRS scores of 3-6. CONCLUSIONS: We conclude that warning headaches diagnosed by interview are not a product of recall bias but are the result of actual leaks from aneurysms.

Sequential changes in MR water proton relaxation time detect the process of rat brain myelination during maturation.

For better understanding of the behavior of water molecules in the animal brain, changes in magnetic resonance water proton relaxation processes were studied in the rat during maturation. Midbrains of male Wistar rats were removed at various time points ranging from 2 to 70 days after birth. Changes in relaxation time (water proton longitudinal relaxation time by the inversion recovery, and water proton transverse relaxation time by the spin echo and the Carr-Purcell-Meiboom-Gill pulse sequence (CPMG)) and water content were then determined for various stages of brain development. During maturation both water proton longitudinal relaxation time and water proton transverse relaxation time values decreased and this finding paralleled the decline in water content. Using the CPMG pulse sequence, the transverse relaxation time values were observed to separate into two components after 21 days. Morphologically, the most prominent change at the matured stage of midbrain development in the rat is myelination. Water proton relaxation time, which can be estimated using the CPMG pulse sequence, showed a close correlation with myelination in the central nervous system.

A flexible sutureless intraluminal graft that becomes rigid after placement in the aorta.

A new sutureless intraluminal graft has been developed with a ring made of a coiled, overlapping, stainless steel spring with ratchets in one overlapping end. This graft is flexible during insertion but becomes rigid after proper intraaortic placement as the spool is dilated and the ratchest lock into position. The new graft was implanted in 10 dogs and was evaluated histologically and angiographically at various intervals. No ring dislodgment, aortic rupture, stenosis, or aneurysmal dilation was observed. The flexible component of this graft allows it to be introduced and secured in place easily and provides a technical advantage compared with the clinically used rigid intraluminal graft.

Computer-assisted interactive three-dimensional planning for neurosurgical procedures.

We have used three-dimensional reconstruction magnetic resonance imaging techniques to understand the anatomic complexity of operative brain lesions and to improve preoperative surgical planning. We report our experience with 14 cases, including intra- and extra-axial tumors and a vascular malformation. In each case, preoperative planning was performed using magnetic resonance imaging-based three-dimensional renderings of surgically critical structures, such as eloquent cortices, gray matter nuclei, white matter tracts, and blood vessels. Simulations, using the interactive manipulation of three-dimensional data, provided an efficient and comprehensive way to appreciate the anatomic relationships. Interactive three-dimensional computer-assisted preoperative simulations provided otherwise inaccessible information that was useful for the surgical removal of brain lesions.

Magnetic resonance cisternography for visualization of intracisternal fine structures.

OBJECT: To assess its usefulness in demonstrating cisternal anatomy, the authors investigated magnetic resonance (MR) cisternography in which a heavily T2-weighted turbo spin-echo method was used to visualize normal anatomical fine structures and lesions in the basal cisterns in 20 healthy volunteers and 43 patients. The authors applied peripheral pulse gating, which had been optimized to reduce artifacts in the cisterns attributable to cerebrospinal fluid (CSF) flow. METHODS: The detectability of each cranial nerve was determined in healthy volunteers. The first, second, and third nerves and the seventh-eighth nerve complex were clearly visualized in all participants; the fifth nerve was clearly seen in 80% and the sixth cranial nerve in 50%. The fourth nerve and the ninth through 12th nerves were difficult to identify individually, except in some volunteers. To reduce artifacts caused by fast CSF flow, we determined the delays as a function of the time elapsed between two consecutive peaks of pulse wave in a peripheral pulse gate (P-P interval) at which there was reversal of flow direction to minimize the CSF flow-related artifact. Using peripheral pulse gating and a time delay of 30% of the R-R interval, the authors succeeded in minimizing the CSF flow-related artifacts. Magnetic resonance cisternography appears to be very useful for demonstrating intracisternal fine anatomy and enhancing the contours of the juxtacisternal lesion. A minute amount of CSF interposed between lesions and normal structures such as nerves, vessels, or bone structures can be detected by means of this sequence. In patients with facial spasm, axial images and oblique coronal images obtained in a plane parallel to the seventh-eighth cranial nerve complex demonstrated vascular compression in all 13 patients. The MR cisternography finding of compression was confirmed in all nine patients who underwent microvascular decompression. CONCLUSIONS: Magnetic resonance cisternography appears to show great promise for evaluation of patients with neurovascular compression or tumors in and around the basal cisterns; the procedure adds only a small amount of imaging time.

Thoracic spinal stenosis: experience with seven cases.

The authors report seven cases of thoracic spinal stenosis caused by thickening of the laminar arch and facet joints. Claudication was a prominent clinical feature of this disorder. Motor and sensory abnormalities were found in all cases with either segmental or peripheral distribution. Diagnosis was best made from the computerized tomography scans. Treatment consisted of extensive posterior decompression including medial facetectomy, resulting in satisfactory improvement in five of the seven patients. A review of the literature regarding this disorder is presented.

Intracranial compartment volumes in patients with enlarged ventricles assessed by magnetic resonance-based image processing.

Magnetic resonance image-based computerized segmentation was used to measure the volumes of the brain, gray and white matter components, and to identify regions with prolonged enhancement on T2-weighted imaging, such as periventricular or deep white matter hyperintensities. The authors also determined the volumes of the ventricles and subarachnoid space in control subjects and in patients with: 1) aqueductal stenosis (AS); 2) other causes of obstructive hydrocephalus (OH); 3) Alzheimer's disease (AD); and 4) normal-pressure hydrocephalus (NPH). In AS the volume of the brain was smaller, whereas that of ventricles and subarachnoid cerebrospinal fluid space was larger than that of controls. The decrease in brain volume was due primarily to white matter loss. Although in OH the ventricles were larger, the subarachnoid space was smaller than in controls, presumably due to encroachment by the brain, in which the volume remained unchanged. In AD, loss of both gray and white matter resulted in a smaller brain volume, whereas that of ventricles and subarachnoid space was larger than in controls. In NPH patients, only ventricular volume was greater, whereas all other compartments were similar to controls. The brain normally occupies 87% to 92% of the intracranial volume and consequently, as observed in our patients, relatively small decrements in brain size lead to large increments in ventricular and/or extraventricular volumes. The magnitude of such changes differed markedly among our patient groups, and whether such changes prove useful in clinical assessment and differentiation needs to be determined.

Age-related changes in intracranial compartment volumes in normal adults assessed by magnetic resonance imaging.

Magnetic resonance (MR) image-based computerized segmentation was used to measure various intracranial compartments in 49 normal volunteers ranging in age from 24 to 80 years to determine age-related changes in brain, ventricular, and extraventricular cerebrospinal fluid (CSF) volumes. The total intracranial volume (sum of brain, ventricular, and extraventricular CSF) averaged 1469 +/- 102 cm3 in men and 1289 +/- 111 cm3 in women. The difference was attributable primarily to brain volume, which accounted for 88.6% of the respective intracranial volumes in both sexes, but was significantly larger in men (1302 +/- 112 cm3) than in women (1143 +/- 105 cm3). In both, the cranial CSF volume averaged 11.4%. Total intracranial volume did not change with age, although the normalized brain volume of both men and women began to decrease after the age of 40 years. This decrease was best reflected by expansion of the extraventricular CSF volume which, after the age of 50 years, was more marked in men than in women. The volume of the cranial CSF, as determined by MR image-based computerized segmentation, is considerably larger than traditionally accepted and resides mostly extraventricularly. Expansion of CSF volume with age provides a good index of brain shrinkage although evolving changes and growth of the head with age tend to confound the results.

The neurobiology of normal pressure hydrocephalus.

Normal pressure hydrocephalus (NPH) is an intriguing problem in cerebrospinal fluid (CSF) and brain parenchymal physiology. This article presents what is known about its pathophysiology as well as its clinical presentation and treatment.

Spontaneous cervical epidural hematoma.

The authors report a case of spontaneous cervical epidural hematoma in a 13-year-old boy who exhibited hematoma recurrence 3 years after the first incidence. A review of the literature indicates very few reports of the recurrence of spinal epidural hematoma.

A diabetic case with hemoglobin J-Meerut and low HbA1C levels.

A diabetic patient with hemoglobin (Hb) J-Meerut and low HbA1C levels is reported. An automatic glycohemoglobin analyzer used for the determination of HbA1C revealed an abnormal peak of the peripheral blood obtained from a Japanese female with diabetes. She showed a lower HbA1C level (3.7%) than expected from her fasting plasma glucose (172 mg/dl). High performance liquid chromatography and isoelectric focusing indicated that her abnormal hemoglobin was Hb J-Meerut [alpha 120(H3)Ala-->Glu] and it accounted for 28.3% of the total hemoglobin. Abnormal hemoglobinemia should be considered when a major discrepancy between the levels of HbA1C and fasting plasma glucose is observed.

[Porencephaly. Case report].

A case of porencephaly in a 33-year-old male is presented. The patient exhibited right hemiparesis and generalized seizures. Computed tomography and, subsequently, craniotomy revealed a cerebral defect in the left parietal lobe, which communicated with the lateral ventricle. On angiography and at surgery, the cortical branches of the middle cerebral artery were found to be stretched over the surface of the cyst. Histopathological examination showed the outer membrane of the cyst to consist of arachnoid, subarachnoid space, vessels, pia mater, and a layer of degenerative brain tissue on histology. The diagnosis of porencephaly and its differentiation from arachnoid cyst are discussed.

[A case report: persistent primitive hypoglossal artery aneurysm].

The authors describe a case of persistent primitive hypoglossal artery aneurysm in a 42-year-old woman who had complained of headache, mainly in the occiput, for 5 days prior to admission. Because of a sudden exacerbation of the headache associated with vomiting, she was hospitalized on July 31, 1988. On admission, a cranial computed tomography scan demonstrated a high density lesion in the basal cisterns which suggested subarachnoid hemorrhage (SAH). Right carotid angiography revealed a persistent primitive hypoglossal artery and an aneurysm arising from this artery at the junction of the posterior inferior cerebellar artery. Bilateral vertebral arteries were shown to be hypoplastic. This was followed by a right suboccipital craniectomy on the 6th hospital day at which time a neck clipping was made. Her postoperative course was uneventful. On discharge on August 22, she was ambulatory and had no neurological deficit except for a mild hoarseness which developed after surgery. Well over one hundred cases of persistent primitive hypoglossal artery aneurysm have been reported. However, as far as we could discern, there have been only 9 cases of persistent primitive hypoglossal artery aneurysm including this present case. Most of the cases had SAH due to the rupture of these aneurysms with favorable outcome after the surgery. In addition, some embryological considerations were made.

[Delayed ischemic neurological deficit that developed over 15 days after subarachnoid hemorrhage].

We retrospectively studied subarachnoid hemorrhage (SAH) patients with delayed ischemic neurological deficit (DIND), and analyzed the factors causing extremely late onset of deficits occurring over 15 days after onset of the SAH. Among 605 patients with SAH, 201 (33%) developed DIND. Among DIND patients, 137 had undergone early aneurysm surgery. In these 137 patients, onset date of DIND was definite in 131 patients. Six patients (5%) developed DIND over 15 days after SAH. All 6 had asymptomatic angiographical vasospasm and infections, most often meningitis, before the onset of DIND. Compared with cases in which there was ordinary onset of DIND, other statistically significant factors among these 6 patients were intracerebral hemorrhage, sepsis and meningitis. We suspect that DIND were manifested subclinically in the early period because of the associated hyperdynamic hemodynamics resulting from sepsis in these patients.

[Clinical application of the central somatosensory conduction time (CCT)].

We tried to prove the usefulness of CCT as an index of cerebral functions. CCT, regional cerebral blood flow (CBF) and CT scan findings were studied in 213 neurological patients with CVD (66 cases), cerebral tumors (66 cases) and head traumas (81 cases). The technique of CCT recording was modified from that of Jones (1977) using CADWELL 5200 system. CCT was defined as the difference of the peak latency between N13 recorded at the C-7 vertebral electrode and N20 recorded at the somatosensory cortex. The control CCT in normal volunteers (N = 20) was 5.7 +/- 0.4 msec. RCBF was measured with 133 Xe intra carotid injection method of Lassen & Ingvar using gammacamera (DEC GAMM 11/34). CCT tended significantly to become more prolonged in affected hemisphere than in unaffected hemisphere of patients with three groups (CVD, tumor and trauma) (p less than 0.01). Forty percent reduction of control rCBF caused a prolongation of CCT over 7 msec. The degrees of CCT prolongations appeared to be proportional to the degree of rCBF diminution. Prolongation of CCT was remarkable in the side of low density area on CT scan. The prolongation of CCT were revealed in the patients before they did not manifest their neurological deficits especially in the disease of metastatic tumors and glioma. In the case of patients with trauma who we could follow to measure rCBF, CCT tended to become shorten as rCBF increased till normal range. CCT was not significantly prolonged in congenital hydrocephalus.(ABSTRACT TRUNCATED AT 250 WORDS)

[Renal protection in acute neurosurgical diseases--effect of a low dose dopamine with reference to acute renal failure and hypernatremia in patients with dehydration].

The authors reviewed the effect of low dose dopamine administration (1-5 micrograms/kg/min) in neurosurgical patients with acute renal failure (5 cases) or hypernatremia (7 cases) in whom cerebral dehydration therapy for intracranial hypertension was thought to be causative of these disorders. Cases with hypernatremia (serum sodium over 155 mEq/l) were considered in the stage of impending acute renal failure as in the majority of cases serum creatinine levels were mildly elevated while urinary sodium was markedly diminished. Associated with systemic hypovolemia, in cases with acute renal failure (with serum creatinine over 3.5 mg/dl and urinary output of less than 20 ml/hr for more than 4 hour duration) the urinary sodium levels were less than 20 mEq/l. In all the cases treated by low dose dopamine, urinary output and sodium increased within 6 hours and in the following 24 hours stabilized urinary output with its elevated sodium (some 100 mEq/l) was obtained. As the result, elevated urea-nitrogen or serum sodium was rather easily washed out and the patients were kept adequately hydrated afterwards. Any complications such as aggravation of cerebral edema or convulsive disorder were not associated with this regime. The authors, therefore, would emphasize that low dose dopamine administration resulting in sodium diuresis and increase in renal blood flow is a practical way of method in treating patients with hypernatremia or acute renal failure caused by hyperosmolar agent infusion in their acute stage.