Lesions of the Pancreatic Islets Produced in Cats by Administration of Glucose

Hydropic degeneration of the islands of Langerhans and permanent severe diabetes mellitus have followed the prolonged injection of intraperitoneal glucose-saline solution in normal as well as in partially depancreatized cats. Positive results were associated with prolonged hyperglycemia. These findings add further evidence in support of the hypothesis that a sustained elevation of blood glucose may, under certain conditions, lead to the production of damage to the islands of Langerhans in this species. Besides hyperglycemia, other disturbances which might be responsible wholly or in part for the island lesions are under study.

IgG in brain correlates with clinicopathological damage in HTLV-1 associated neurologic disease

OBJECTIVE

To test the authors' hypothesis that antibody deposition in autopsy specimens from patients with human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) would correlate with CNS damage.

METHODS

Endogenous immunoglobulin G (IgG) was detected using antihuman IgG in autopsy tissues from HAM/TSP and control patients. IgG was isolated from the CSF, CNS, and sera of patients with HAM/TSP and tested for reactivity to heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1), an autoantigen recently associated with molecular mimicry in HAM/TSP.

RESULTS

In situ IgG localized to elements of the corticospinal system including neurons of the frontal cortex and precentral gyrus, as well as throughout axons in subcortical white matter, periventricular white matter, posterior limb of the internal capsule, midbrain, pons, and medulla. Similarly, there was IgG deposition within the posterior-column/medial lemniscal sensory system, including the arcuate fibers of the cranial-cervical junction, the nucleus cuneatus, and throughout the course of the medial lemniscus in the medulla, pons, and midbrain. IgG from brain, CSF, and serum of the patients with HAM/TSP showed immunoreactivity with hnRNP A1.

CONCLUSION

Patients with HAM/TSP develop antibodies specific for neurons and axons that are preferentially damaged in the CNS.

Gliomas of the tectum and periaqueductal region of the mesencephalon

Gliomas that arise in the tectal and periaqueductal region of the mesencephalon usually present with hydrocephalus secondary to occlusion of the aqueduct of Sylvius. A review of 486 brain tumors in children treated during a 5-year period revealed 6 children with gliomas of the tectal plate. The 6 children were shunted for hydrocephalus, presumed secondary to aqueductal stenosis, prior to establishing the diagnosis of tectal plate glioma. No abnormalities were noted on the initial, uncontrasted computed tomography (CT) scans. The tumors are isodense without contrast enhancement which makes the CT diagnosis difficult. Magnetic resonance imaging (MRI) is diagnostic and demonstrates the characteristic enlargement of the tectum with increased density on T2 images. T1 density and gadolinium enhancement are variable. Pathological confirmation was obtained by open biopsy in 2 patients, a stereotaxic biopsy was performed on 2 children; 2 children were not biopsied. The tumor histology obtained was that of pilocytic astrocytoma. Two patients were treated with radiation therapy at the time of diagnosis. One child was followed closely and subsequently irradiated after tumor progression. All patients in this series are alive and functioning adequately 2-10 years after the onset of symptoms.

Hippocampal sclerosis in a two-year-old with temporal lobe epilepsy: case report with pathological confirmation

The case of a 2-year-old girl who underwent anterior temporal lobectomy for intractable epilepsy is described. Hippocampal sclerosis (HS) was present on histopathological examination. We believe this to be one of the youngest reported patients with pathologically confirmed HS. This has implications for the possible etiology of HS.

Synaptophysin immunoreactivity in temporal lobe epilepsy-associated hippocampal sclerosis

We have previously devised a semiquantitative grading system for hippocampal sclerosis (HS) in specimens resected for intractable temporal lobe epilepsy. The grades range from zero to four based on the amount and distribution of neuronal loss and gliosis. In the present study hippocampal sections from 25 patients who had temporal lobe epilepsy and had previously been assigned a grade were examined with synaptophysin immunohistochemistry, and the synaptic content in specific hippocampal fields was correlated with the results of the HS grading system. There was evidence of both significant synaptic loss and increased synaptic density in different fields of the hippocampus with increasing HS. A marked decrement of synaptic inmmunostaining was present in fields CA1 and CA4 that were highly correlated with HS grade. Sector CA4 seemed to respond in a more graded or continuous way to the pathological insults occurring in temporal lobe epilepsy than did CA1, which appeared to exhibit an all or nothing response. Also, while the width of the outer part of the molecular layer of the dentate (mid) gyrus decreased with increasing HS grade, the inner part of the mid became wider and showed an increased synaptic density so that the overall width of the mid was increased in the high-grade group. We conclude that quantitative measurement of synaptic loss in CAI and CA4 using synaptophysin immunohistochemistry is a sensitive method for detecting HS and correlates well with the empirically derived HS grading scale, with CA4 exhibiting a more graded response than CA1. In addition, a plasticity response in the inner part of the mld in patients with high-grade HS has been confirmed and quantitated.

Prediction of presence of hippocampal sclerosis from intracarotid amobarbital procedure memory asymmetry scores and epilepsy on set age

Identification of the pathological status of the hippocampus prior to surgery is important since the absence of hippocampal sclerosis (HS) carries risks to memory function following anterior temporal lobectomy (ATL). We studied 62 patients undergoing ATL (31 L, 31 R) for intractable epilepsy of temporal lobe origin in whom no pathology was identified apart from HS. An intracarotid amobarbital procedure (IAP) was performed as part of the preoperative evaluation. All patients were left hemisphere dominant for language. IAP memory testing was according to the protocol of Loring. We examined IAP memory asymmetry scores at four levels of difference (<2, > or =2, > or =4, > or =6) as a function of the presence (HS+) or absence (HS-) of HS. A logistic regression analysis was performed with HS+ as the dependent variable, and age at onset of epilepsy, age at time of surgery, gender, side of surgery and significant IAP memory asymmetry as independent variables. At each level of memory asymmetry, onset age and memory asymmetry were the only predictors of HS+. Younger age at onset was associated with HS+. Curves were constructed showing probability of HS+ for age at onset for each level of asymmetry. These can be used to predict the likelihood of presence of HS based on age at onset of epilepsy and the IAP memory asymmetry score. It is concluded that IAP memory asymmetry scores reflect the functional and pathological status of the hippocampus, and greater asymmetry increases the probability of finding HS in the resected hippocampus.

Synaptophysin immunohistochemistry densitometry measurement in resected human hippocampus: implication for the etiology of hippocampal sclerosis

Synaptophysin (SY) is a protein expressed at presynaptic vesicles. SY immunohistochemistry (IHC) was undertaken in surgically resected hippocampal specimens from 25 patients with intractable epilepsy. All were investigated with chronic ictal EEG videotelemetry, which showed a temporal onset in each case, and all had normal magnetic resonance imaging (MRI). The density of reaction product of SY IHC was used to generate optical density (OD) measurements as an estimate of synaptic density in CA1 and CA4 fields (ODCA1 and ODCA4), and inner third and outer two-thirds of the molecular layer of the dentate gyrus (ODIML and ODOML). There was significant correlation between ODCA1 (r=0.619, P=0.001) and ODCA4 (r=0.639, P=0.001) and onset age of epilepsy. There was no correlation between ODCA1 and duration of epilepsy. There was correlation between ODCA4 and duration (r=-0.412, P=0.041), but partial correlations showed no significant correlation between ODCA4 and duration when controlling for onset, although correlation between ODCA4 and onset when controlling for duration remained significant (r=0.536, P < 0.01). Univariate ANOVA revealed onset age to be the only predictor of ODCA1 and ODCA4. Chronological age and duration were not predictors. There was no correlation between ODIML or ODOML and either onset age or duration. ODIML and ODOML were not predicted by onset age, duration or chronological age. These findings support the hypothesis that the major cause of hippocampal sclerosis is an age specific insult rather than the result of repeated seizures.

Reversal of cerebral vasospasm using an intrathecally administered nitric oxide donor

OBJECT

Intrathecal bolus administration of (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)aminio]diazen++ +-1-ium-1,2-diolate (DETA/NO), a long half-life diazeniumdiolate-class nitric oxide (NO) donor, was evaluated for safety and efficacy in the treatment of delayed cerebral vasospasm in a canine model of subarachnoid hemorrhage (SAH).

METHODS

The baseline basilar artery (BA) diameter of 25 dogs was measured with the aid of angiography on Day 0. Vasospasm was then induced by intracisternal injection of autologous arterial blood on Days 0 and 2. Repeated arteriography on Day 7 revealed an average BA diameter of 58% of baseline. Each dog was then randomized to one of four groups: a pathology control group (SAH only, four animals); a treatment control group (SAH plus 2 micromol of the inactive drug carrier DETA, eight animals); a low-dose treatment group (SAH plus 0.2 micromol DETA/NO, six animals); or a high-dose treatment group (SAH plus 2 micromol DETA/NO, six animals). The drugs were administered in a 2-ml intrathecal bolus via the cisterna magna. Arterial caliber was monitored by angiography over the subsequent 4 hours. A 2-micromol dose of the drug was then given and serial arteriography continued for an additional hour to screen for tachyphylaxis. Intracranial pressure and respiratory and hemodynamic parameters were continuously monitored. Histopathological analyses of the animals' brains were performed after the dogs were killed on Day 8. The drug DETA/NO produced reversal of vasospasm in a dose-dependent fashion that roughly followed a double exponential time course. Doses of 2 micromol DETA/NO resulted in restoration of the angiographically monitored BA diameter to the prevasospasm size at 1.5 hours posttreatment, and this was sustained at 88% of baseline at 4 hours (p < 0.01, independent samples t-test). By contrast, the treatment control group remained on average at 54% of baseline diameter. The low-dose treatment group achieved only partial and more transitory relaxation. Histopathological analyses showed findings consistent with chronic SAH but did not demonstrate any toxicity associated with the NO donor. No adverse physiological changes were seen.

CONCLUSIONS

This study indicates that long-acting NO donors are potentially useful as agents to restore circulation in patients suffering from cerebral vasospasm.

Neuropsychological outcome following anterior temporal lobectomy in patients with and without the syndrome of mesial temporal lobe epilepsy

The nature, pattern, and degree of neuropsychological change following anterior temporal lobectomy (ATL) were examined as a function of the presence or absence of the syndrome of mesial temporal lobe epilepsy (MTLE). Fifty-four patients exhibited the syndrome of MTLE, while 34 patients were without the syndrome (non-MTLE). The test-retest performance of a group of 40 epilepsy patients who did not undergo surgery was used to derive regression-based estimates of test-retest change. Overall, the MTLE group did not show significant cognitive decline following ATL. In contrast, the left non-MTLE group showed significant declines on verbal memory, confrontation naming, and verbal conceptual ability. Further, verbal memory was the most substantial area of decline, and was independent of seizure outcome. Clinical and theoretical implications of these findings are discussed.

Naming decline after left anterior temporal lobectomy correlates with pathological status of resected hippocampus

PURPOSE

To evaluate the determinants of postoperative change in visual confrontation naming ability and the differential sensitivity of two common tests of confrontation naming.

METHODS

In a group of 99 patients undergoing lobectomy of the left, language-dominant anterior temporal lobe, we examined naming ability using two measures: the 60 item Boston Naming Test (BNT), and the Visual Naming (VN) subtest of the Multilingual Aphasia Examination (MAE). ATL entailed resection of lateral temporal lobe followed by microsurgical complete removal of hippocampus. Language mapping was not performed. The status of the resected hippocampus was graded on a scale 0-4 of hippocampal sclerosis (HS). A dichotomous grouping HS- (grades 0 and 1, n = 34) and HS+ (grades 3 and 4, n = 61) was effected. Age at surgery, age of epilepsy onset, sex, extent of lateral temporal resection, Full-Scale IQ (FSIQ), and preoperative naming scores were also examined as potential predictors of pre- versus postoperative naming change.

RESULTS

Preoperative BNT and VN scores were significantly worse for HS+ than for HS- (BNT, p < 0.05; VN, p = 0.001). Postoperatively, BNT and VN scores significantly declined for HS- as compared with HS+ patients (p < 0.001). For individual risk, the 90th centile of reliable change index (RCI) was used. By this criterion, of the total sample, 39% evidenced decline on the BNT and 17% evidenced decline on the VN. Logistic regression analysis with backward elimination showed HS to be the only predictor of decline in BNT and HS and sex to be the only predictors of VN decline. Males were more at risk than females. Age, age at onset, extent of lateral resection, preoperative scores, and FSIQ were not predictors. Using age at onset as a proxy for HS+/HS- we calculated probabilities for naming decline for given onset age.

CONCLUSIONS

Both preoperative and postoperative change in naming ability are associated with the pathological status of the hippocampus. The potential interpretations and implications of these findings are discussed.

Neuropsychological outcome following anterior temporal lobectomy in patients with and without the syndrome of mesial temporal lobe epilepsy

The nature, pattern, and degree of neuropsychological change following anterior temporal lobectomy (ATL) were examined as a function of the presence or absence of the syndrome of mesial temporal lobe epilepsy (MTLE). Fifty-four patients exhibited the syndrome of MTLE, while 34 patients were without the syndrome (non-MTLE). The test-retest performance of a group of 40 epilepsy patients who did not undergo surgery was used to derive regression-based estimates of test-retest change. Overall, the MTLE group did not show significant cognitive decline following ATL. In contrast, the left non-MTLE group showed significant declines on verbal memory, confrontation naming, and verbal conceptual ability. Further, verbal memory was the most substantial area of decline, and was independent of seizure outcome. Clinical and theoretical implications of these findings are discussed.

Reorganization of verbal memory function in early onset left temporal lobe epilepsy

The purpose of this investigation was to examine the issue of reorganization of verbal memory function following early insult to the left mesial temporal region. It was hypothesized that reorganization of memory function was most likely to occur in those patients with an early age of seizure onset who have a more limited degree of extra-hippocampal neuropathology. Fifty-four patients with epilepsy of unequivocal left temporal lobe origin were classified into four groups on the basis of the presence/absence of hippocampal sclerosis and degree of postoperative seizure relief. Measures of verbal learning and memory as well as nonmemory measures were administered both before and 6 to 8 months after anterior temporal lobectomy. Findings were consistent with the reorganization proposal. The clinical and theoretical significance of the findings are discussed.

Reduction of peridural fibrosis after lumbar laminotomy and discectomy in dogs by a resorbable gel (ADCON-L)

STUDY DESIGN

A canine lumbar laminotomy and discectomy model was used to evaluate the effects of a resorbable gel, ADCON-L (Gliatech Inc., Cleveland, OH), in reducing peridural scar formation and to assess the healing progress of immediately adjacent normal structures.

OBJECTIVES

To compare peridural scar formation and anulus fibrosis healing with and without the use of ADCON-L in an animal model that closely replicates the common human surgical procedure.

SUMMARY OF BACKGROUND DATA

ADCON-L has been shown to reduce the development of peridural scars in rat, rabbit, and canine laminectomy models in previous investigations; discectomies were not performed in these previous studies, however, and thus anular healing could not be assessed.

METHODS

Seven adult mongrel dogs underwent a three-level unilateral lumbar hemilaminotomy and anular fenestration. In each dog, the ADCON-L was applied to two randomly assigned sites around the discectomy, the nerve roots, and the hemilaminotomy. The third site underwent surgery, but was left untreated (sham surgery only). The canines were killed 8 weeks after surgery, and a gross anatomic assessment of scar formation was done using microdissection by an observer blinded to treatment. A numerical rating system was developed to assess the relative amount and tenacity of the anterior scarring (discectomy site) and posterior scarring (hemilaminotomy site). The healing of the anular defect was assessed histologically.

RESULTS

ADCON-L significantly reduced peridural fibrosis in this lumbar discectomy model compared with the sham treated sites (p < 0.05). Further, the superficial layers, the posterior longitudinal ligament, and the anulus fibrosus healed well in the ADCON-L treated sites.

CONCLUSIONS

ADCON-L reduced local peridural fibrosis after lumbar laminotomy and discectomy without impacting the healing of the surrounding tissues.

Solitary spinal cord sarcoidosis without other manifestations of systemic sarcoidosis

We report a biopsy-proven case of sarcoidosis limited to the spinal cord and responsive to treatment with oral corticosteroids. Involvement of the spinal cord by systemic sarcoidosis is uncommon and is associated with several unusual pathological and radiological characteristics that may contribute to its misdiagnosis and subsequent mismanagement. The importance of these unusual characteristics is greatly amplified in solitary spinal cord sarcoidosis because there are no systemic findings to suggest a sarcoid etiology.

Intractable epilepsy due to meningitis: results of surgery and pathological findings

Between 1986 and 1992, among a total of 668 craniotomies performed for intractable epilepsy, 13 (1.9%) patients had a presumed aetiology of a previous episode of meningitis. Twelve were investigated with chronic electrocorticography with subdural electrodes which showed mesial temporal onset in eight, regional temporal onset in three and bilateral diffuse onset in one. One patient underwent corpus callosotomy and 12 anterior temporal lobectomy (ATL) (6L, 6R). The pathology in the resection cases was hippocampal sclerosis in six and gliosis in six. Mean length of follow up was 3 years (range 1-6 years). Ten of the 12 (83%) ATL patients were seizure free (six off medications). Two ATL patients and the callosotomy patient were significantly improved. It is concluded that in patients where the presumed aetiology of intractable epilepsy is meningitis and widespread damage may therefore be expected, this does not necessarily indicate multifocality, and the prognosis following resective surgery appears to be good.

Choroid plexus histoplasmoma: clinical, pathologic, and imaging findings

Histoplasmosis of the choroid plexus has not previously been described. We report its occurrence, as well as its clinical, pathologic, and imaging characteristics in one case. Clinically, our patient's choroid plexus lesion produced encephalopathy and third nerve palsy. On imaging it appeared as a hemorrhage or calcification. Cerebrospinal fluid studies were consistent with a chronic meningeal process uncomplicated by hemorrhage. Stereotactic biopsy of the choroid plexus was required to establish the diagnosis of cerebral histoplasmosis. Pathologic examination also revealed prominent abnormal calcification, which permitted the lesion of masquerade as a hemorrhage on computed tomographic and magnetic resonance images.

Cervical kyphosis after resolution of myopathic head drop. A case report

STUDY DESIGN

This is a case report.

OBJECTIVES

To present a case of cervical kyphosis after resolution of myopathic head drop.

SUMMARY OF BACKGROUND DATA

Myopathic head drop is a severe and persistent local myopathy that never progresses beyond the neck extensor muscles.

METHODS

A case is reported of a hospitalized psychiatric patient who experienced the sudden onset of severe neck extensor weakness consistent with myopathic head drop.

RESULTS

Although myopathic head drop resolved after 2 years, it left a disabling residual skeletal deformity of the cervical spine.

CONCLUSIONS

Myopathic head drop may be a cause of cervical kyphosis.

Hippocampal sclerosis and verbal encoding ability following anterior temporal lobectomy

Previous research has shown that the degree of verbal memory decline following left anterior temporal lobectomy (ATL) is inversely related to the extent of neuronal dropout in resected left hippocampus. The goal of this investigation was to clarify further the nature of the free recall impairment and to determine the relative contribution of verbal retrieval and encoding processes. Seventy-six patients who underwent left (n = 46) or right (n = 30) ATL were classified according to the presence or absence of hippocampal sclerosis and pre- to postoperative changes in free recall, cued recall and recognition memory for verbal material were examined. Surgically induced free recall impairments were selectively associated with resection of nonsclerotic left hippocampus and represented a 29-35% decline in verbal learning ability. These free recall deficits were due to postoperative impairment in verbal encoding efficiency, not retrieval difficulties. Assessment of false positive recognition errors indicated that resection of nonsclerotic left hippocampus selectively impaired the ability to encode stimulus uniqueness within correct semantic fields. The clinical and theoretical significance of these results are discussed.

Relationship of hippocampal sclerosis to duration and age of onset of epilepsy, and childhood febrile seizures in temporal lobectomy patients

Controversy exists as to whether hippocampal sclerosis (HS) is a preexisting cause or a consequence of seizures. We investigated 122 consecutive patients who underwent anterior temporal lobectomy for intractable epilepsy between 1989 and 1992. MRI scans were normal apart from evidence of HS in 5 cases. The degree of HS was graded from 0 to 4. There was a significant inverse correlation between age of seizure onset and grade of HS (P < 0.0001), and a positive correlation between duration of epilepsy and grade of HS (P < 0.001). Using a dichotomous grouping of HS (HPSC - for grades 0 and 1 [no/mild HS], and HPSC + for grades 3 and 4 [moderate/marked HS]), there was a positive correlation between HPSC + and a history of childhood febrile seizures (CFS) (P = 0.003), earlier age of onset of epilepsy (P < 0.001) and longer duration of epilepsy (P < 0.001). There was no correlation with history of particularly prolonged individual seizures. Partial correlations after controlling for age at onset of epilepsy showed that there was no longer a significant relationship between HPSC + and duration of epilepsy. After controlling for duration of epilepsy, the relationship between HPSC + and age of onset remained significant (P < 0.001). The correlation between HPSC + and CFS, controlling for age at onset, was not significant. A series of logistic regression analyses showed age at onset to be the only predictor of HPSC +. It is concluded that this is supportive evidence for preexisting HS being a cause of temporal lobe epilepsy and not a consequence of seizures.

Solitary focal demyelination in the brain as a paraneoplastic disorder

Solitary focal demyelination (SFD) in the brain is an uncommon and poorly understood disorder of uncertain etiology that may represent an intermediate entity between multiple sclerosis and acute disseminated encephalomyelitis. In a few reported cases of SFD, the patient was briefly noted to have a nonneurological malignancy. We studied two patients who had solitary focal lesions in the brain. Utilizing magnetic resonance imaging and tissue biopsy, we found the characteristics of the brain lesions in these two patients to be those of SFD. In our combined experience over the past 10 years, we have encountered no similar brain lesions at our medical center. We found it remarkable that both of these patients also had malignancy outside of the nervous system. One had a seminoma, and the other a lymphoma. We conclude that some cases of SFD in the brain may occur as a paraneoplastic disorder associated with nonneurological malignancies.

Reports by patients and their families of memory change after left anterior temporal lobectomy: relationship to degree of hippocampal sclerosis

Memory decline represents the primary neuropsychological morbidity of anterior temporal lobectomy. Recent investigations using laboratory tests of memory have reported an association between the neuropathological status of the resected left mesial temporal region and memory outcome, with adverse memory outcome associated with a lack of significant left hippocampal pathology. The purpose of this investigation was to examine the relationship between the reports by the patients and their families of observed postoperative changes in day-to-day memory function and the degree of hippocampal sclerosis in resected left mesial temporal lobes. Twenty patients and a close family member (parent or spouse) of each of the patients completed standardized questionnaires assessing pre- to postoperative changes in verbal and spatial memory; these were related to the neuropathological findings. The results indicated that patients without left hippocampal sclerosis reported significantly worse memory outcome than those with hippocampal sclerosis. The ratings provided by the relatives of the patients yielded a comparable effect, and objective memory tests supported the reports by the patients and their families. The neuropsychological findings associated with left hippocampal pathology are of clinical significance and should be considered in surgical evaluation and in the counseling process.

Opioid and tachykinin neuropeptides in prolactin-secreting human pituitary adenomas

Two opioid neuropeptides, methionine enkephalin (ME) and beta-endorphin (BE), and one tachykinin neuropeptide, substance P (SP), were quantified in 10 prolactin (PRL)-secreting human pituitary adenomas and in 10 control human pituitaries. Immunohistochemical techniques provided appropriate staining for PRL. Reversed-phase high performance liquid chromatography (RP-HPLC) was used to purify these three neuropeptides before their analysis, radioimmunoassay (RIA) was used for the quantification of SP-like immunoreactivity (SP-LI), and liquid secondary-ion mass spectrometry (LSIMS) was used for the qualitative and quantitative analysis of ME and a tryptic peptide of BE. This study shows that, for 90% of the cases studied here (excluding one hypothyroidism case), the tachykinin A neuropeptide SP-LI level is decreased, the POMC peptide BE level is not altered, and the proenkephalin A neuropeptide ME level is increased in these PRL-secreting tumors.

Declarative memory following anterior temporal lobectomy in humans

This study hypothesized that verbal memory decline following anterior temporal lobectomy (ATL) is associated with a lack of significant neuropathology in resected left, but not right, hippocampus and is limited to measures of episodic memory only. Tests of immediate (digit span), semantic (visual naming), and episodic memory as measured by the California Verbal Learning Test (CVLT) were administered before and 6 months after resection of the anterior left (n = 36) or right (n = 26) temporal lobe. There were no effects of hippocampal pathology on measures of immediate or semantic memory for either ATL group or for episodic memory for the right ATL group. Left ATL patients who demonstrated no/mild hippocampal sclerosis exhibited significantly greater postoperative decline in episodic memory compared with those with moderate/marked hippocampal sclerosis on multiple CVLT indices (recall measures, learning characteristics, and contrast measures).

Declarative memory following anterior temporal lobectomy in humans

This study hypothesized that verbal memory decline following anterior temporal lobectomy (ATL) is associated with a lack of significant neuropathology in resected left, but not right, hippocampus and is limited to measures of episodic memory only. Tests of immediate (digit span), semantic (visual naming), and episodic memory as measured by the California Verbal Learning Test (CVLT) were administered before and 6 months after resection of the anterior left (n = 36) or right (n = 26) temporal lobe. There were no effects of hippocampal pathology on measures of immediate or semantic memory for either ATL group or for episodic memory for the right ATL group. Left ATL patients who demonstrated no/mild hippocampal sclerosis exhibited significantly greater postoperative decline in episodic memory compared with those with moderate/marked hippocampal sclerosis on multiple CVLT indices (recall measures, learning characteristics, and contrast measures).

The reduction of postlaminectomy peridural fibrosis in rabbits by a carbohydrate polymer

Spinal peridural fibrosis following total laminectomy in New Zealand White rabbits was significantly decreased by the intraoperative application of GT1587, a semi-synthetic carbohydrate polymer. The application of a similar polymer, GT1043, or phosphate-buffered saline (PBS) was not as effective. Laminectomies were performed at L-2 and L-4 in 25 rabbits. Absorbable gelatin sponge soaked with GT1043, GT1587, or PBS was applied in a blinded fashion to the operative sites, with untreated (sham) laminectomy sites serving as controls. Animals were sacrificed after 2 or 4 weeks. The extent of peridural fibrosis was evaluated by gross microdissection and histological analysis. Dense scar formation and dural adhesions were evident at both time intervals in the sham- and PBS-treated laminectomy sites. The sites treated with GT1587 showed significantly decreased peridural scar formation and dural adhesions, whereas GT1043 treatment caused modest reduction of scar formation at only the 2-week examination. The healing of skin and lumbosacral fascia was not affected by treatment of the laminectomy site with GT1587. These results suggest that GT1587 may prove beneficial in preventing postlaminectomy dural adhesions and peridural fibrosis in humans.

Pathological status of the mesial temporal lobe predicts memory outcome from left anterior temporal lobectomy

This investigation tested the hypothesis that the degree of impairment to memory function caused by an anterior temporal lobectomy (ATL) is inversely related to the pathological status of the resected hippocampus. Specifically, the greatest risk to postoperative memory function should be to patients with no or minimal hippocampal sclerosis, i.e., those with a functional hippocampus. Forty patients who underwent a partial resection of the left (n = 21) or right (n = 19) anterior temporal lobe were administered tests of immediate and delayed verbal and figural memory, both preoperatively and 6 months postoperatively. The degree of postoperative impairment in memory function was then investigated as a function of the degree of hippocampal sclerosis, as determined by a standardized procedure. For a left ATL, an absence or mild degree of hippocampal sclerosis was associated with significantly greater postoperative impairment of both verbal and figural memory, compared with patients with moderate or marked sclerosis. No statistically significant relationship was noted for patients who underwent a right ATL, but the findings were in the same direction for five of six memory measures. It may be possible to predict and avoid surgically induced impairment of memory function among patients who undergo left ATL through the use of preoperative hippocampal volumetric magnetic resonance imaging. Better clinical tests of right hippocampal function are needed to predict the outcome for patients who undergo a right ATL.

Immunocytochemical evidence of lymphocytic derivation of neoplastic cells in malignant angioendotheliomatosis

Neoplastic angioendotheliomatosis is a rare disorder usually characterized by primarily cutaneous or neurological symptoms. Approximately 40 cases of malignant angioendotheliomatosis with primary central nervous system (CNS) symptoms have been reported. Some investigators have postulated a hematopoietic origin for this neoplasm. Most of the literature, however, has perpetuated the idea that the often bizarre symptoms seen with this entity result from neoplastic endothelial cell proliferation within the small vessels of affected organs, including the brain and spinal cord. This report describes the immunohistochemical examination and confirmation of the cell of origin of this neoplasm based on five previously unpublished cases of malignant angioendotheliomatosis with primarily CNS symptoms. It includes the first documentation of a T-cell lymphoma presenting as malignant angioendotheliomatosis. All cases include autopsy findings, and in four cases the diagnosis was made postmortem. One case was proven by stereotactic biopsy, but the patient succumbed as a result of severe intracranial bleeding that occurred at the time of biopsy. Tissues were studied with avidin-biotin peroxidase immunohistochemical techniques using a panel of monoclonal antibodies directed against the leukocyte common antigen, LN-1, LN-2, and anti-Factor VIII, and also using Ulex europaeus agglutinin 1. Based on the results obtained, the authors conclude that the proliferative cells seen within the vessel lumina are of lymphocytic origin and agree that the condition should more properly be designated intravascular lymphomatosis. The therapeutic implications of this conclusion point to the possible administration of chemotherapy and radiotherapy in an effort to achieve remissions in an otherwise relentlessly progressive neurological disorder.

Hyperthermia for the treatment of brain tumors

Brain malignancy, either primary or metastatic, in general is associated with a very poor outcome in spite of the best therapy modern medicine has to offer. The multimodality approach appears to offer the best chance of achieving our goal of improved survival (quality and quantity) and ultimately cure. Hyperthermia, though its application to brain cancer remains experimental, has proven itself in its ability to improve cancer therapy results. There are many methods available to apply hyperthermia to the brain and its application, thus far, has been quite safe. Continued research in this exciting field is warranted.

Genetic hypothesis of idiopathic schizophrenia: its exorphin connection

This brief overview proposes a testable oligogenic model of the inheritance of susceptibility to idiopathic schizophrenia: "abnormal" genes at each of a few complementary loci. The model is based on my assumptions as to the likely genetic abnormalities at possibly four or five interacting loci that would permit exorphins, the opioid peptides from some food proteins, especially glutens and possibly caseins, to go from gut to brain and cause symptoms of schizophrenia. Exorphins may reach the brain cerebrospinal fluid (CSF) in harmful amounts because of their genetically increased, receptor-mediated transcellular passage across the gut epithelial barrier plus decreased catabolism by genetically defective enzymes. A schizophrenia-specific, genetically enhanced affinity for exorphins by opioid receptors influencing dopaminergic and other neurons would permit sustained dysfunction at low CSF exorphin concentrations. Tests of each postulated genetic abnormality are suggested. This model is supported by a variety of evidence, including a significant effect of gluten or its absence on relapsed schizophrenic patients, the high correlation of changes in first admission rates for schizophrenia with changes in grain consumption rates, and the rarity of cases of schizophrenia where grains and milk are rare.

Malignant nerve sheath tumor of the facial nerve: case report and discussion

The third reported case of a malignant nerve sheath tumor of the facial nerve is presented. The clinical course and pathological findings are described and serve as the basis for a discussion concerning malignant nerve sheath tumors arising in the cranial nerves.

Mycobacterium tuberculosis meningitis: a report of twelve cases and a literature review

Twelve recent cases of Mycobacterium tuberculosis meningitis were presented, and the literature was reviewed. There are no particularly new or unique therapies or approaches to the management of this most serious disease. The major obstacle to successful diagnosis and treatment of tuberculous meningitis continues to be a lack of clinical suspicion of its presence. As illustrated in the cases presented, it has been our experience that patients already moribund or nonresponsive do not respond, regardless of the intervention undertaken. The most sensitive and economical method of detecting M. tuberculosis in the CSF may be LPA. However, this has not yet been widely validated or accepted. Larger volumes of CSF should be sent to the laboratory for testing and centifuged to about 5x concentrations before both acid-fast bacilli staining and culture are attempted. If tuberculous meningitis is suspected, three-drug therapy can be started immediately without jeopardizing subsequent culture confirmation of the presence of the TB bacillus. In addition, these patients must be followed closely to detect hydrocephalus at the earliest possible moment. When patients fail to respond to appropriate antituberculosis and pressure-reducing therapy, hydrocephalus should be actively sought by either CT or radioisotope cisternography. Although the decision to proceed to ventricular drainage or shunting must be individually made in adult patients with infection-related hydrocephalus, we agree with others that surgical intervention should be considered early and should be performed if the level of consciousness deteriorates, intracranial pressure increases, or ventricular enlargement or enhancing basal exudates are identified on CT.

Presentation of central nervous system sarcoidosis as intracranial tumors

Five cases of sarcoid presenting as an intracranial tumor are reported. In one instance, the lesion presented as a tumor in the cerebellopontine angle, a site not previously reported for the initial presentation of sarcoid isolated to the central nervous system. The role of computerized tomography, surgery, and steroid therapy is discussed. In the absence of pulmonary involvement, serum angiotensin-converting enzyme levels do not appear to be helpful in predicting steroid response.

Sonographic appearance of callosal agenesis: correlation with radiologic and pathologic findings

Sonographic features are described in six infants in whom total or partial agenesis of the corpus callosum was confirmed by either computed tomographic or pathologic examination. The six patients demonstrated a range of abnormalities involving the neuraxis as well as other systems, notably cardiovascular, gastrointestinal, and genitourinary. Chromosomal abnormalities were present in two patients. The sonographic features of callosal agenesis seen in these patients included: lack of characteristic acoustic interfaces to define the corpus callosum on both coronal and sagittal sonograms; increased separation and parallelism of the bodies of the lateral ventricles; loss of the characteristic convexity of the medial border of the anterior horns of the lateral ventricles; variable prominence of the occipital horns of the lateral ventricles; variable degree of superior extension of the third ventricle; alteration or absence of the cavum septi pellucidi; and radial arrangement of cerebral sulci about the prominent third ventricle. Cases of partial agenesis may show the dysplastic features found in complete agenesis. However, only some of the callosal echoes are present. The sonographic features of partial agenesis in one infant had not been described before.

Is schizophrenia rare if grain is rare?

If, as hypothesized, neuroactive peptides from grain glutens are the major agents evoking schizophrenia in those with the genotype(s), it should be rare if grain is rare. To test this, we analyzed the results of our clinical examinations (e.g., kuru) and observations of anthropologists on peoples consuming little or no grain. Only two overtly insane chronic schizophrenics were found among over 65,000 examined or closely observed adults in remote regions of Papua New Guinea (PNG, 1950-1967) and Malaita , Solomon Islands (1980-1981), and on Yap , Micronesia (1947-1948). In preneuroleptic Europe over 130 would have been expected. When these peoples became partially westernized and consumed wheat, barley beer, and rice, the prevalence reached European levels. Our findings agree with previous epidemiologic and experimental results indicating that grain glutens are harmful to schizophrenics.