Parkinson's disease, chronic hydrocarbon exposure and striatal neuronal damage: a 1-H MRS study.

Several patients with Parkinson' s disease (PD) reveal an history of chronic exposure to hydrocarbon-solvents. Chronic exposure to hydrocarbon-solvents has been proposed as a risk factor for more severe forms of PD with earlier onset of symptoms and reduced response to dopaminergic therapy. A direct correlation between disease severity and exposure degree has been previously shown. Seven exposed PD patients (two with low degree exposure and five with high degree exposure), 10 unexposed PD patients matched for sex, age and Hoehn and Yahr scale (=3 in the "on" phase), and 10 unexposed PD patients matched for sex, age and l-dopa daily intake instead of disease severity (Hoehn and Yahr scale=3.5 in the "on" phase) were studied. Twenty normal subjects without previous exposure to hydrocarbon-solvents and matched for age and sex with HPD patients were studied for comparison. The purpose of the study was to assess neuronal degeneration in the striatum of exposed vs unexposed PD patients. The authors investigated whether neuronal damage/loss was detectable in the lentiform nucleus measuring N-acetylaspartate (NAA) levels by 1-H MRS. Multiple single voxel MRS water-suppressed spectra were obtained also from the white matter and the occipital lobe. NAA was normal in the lentiform nucleus of patients with low exposure as well as in patients with no exposure whereas it was decreased in PD patients with high degree exposure. White matter and occipital lobe NAA content was normal both in exposed and unexposed PD patients. Clinical expression is more severe in PD patients with previous high degree solvent exposure because of the associated post-synaptic damage of the nigro-striatal pathway.

Visualisation of the subthalamic nucleus: a multiple sequential image fusion (MuSIF) technique for direct stereotaxic localisation and postoperative control.

A novel multiple, sequential image fusion (MuSIF) procedure merging stereotaxic CT with frameless magnetic resonance imaging (MRI) is used since June 2000 to visualise and directly localise the subthalamic nucleus (STN) on T2 images. In 13 consecutive Parkinson's cases, intraoperative recording and stimulation verified bilateral electrode implantation guided by fused T2 images. In 85% of sides, final implantation opted for visualised target track. Implanted electrode position on postoperative T2 images matched planned target. Clinical follow-up reproduces literature's best results. This MuSIF technique, effective for direct STN targeting, has practical advantages: MRI can be performed regardless of surgery time; regular MR scanning to correct real image distortion is unneeded; and the need for multiple localising tracks is reduced by enabling us to account for each patient's STN anatomy.

Anatomic and surgical approach to the ethmoidal nerve and parasympathetic innervation of the nasal and cerebral circulation in sheep.

OBJECTIVE: To describe an anatomic and surgical approach to the efferent parasympathetic branches of the pterygopalatine ganglia in sheep, with particular reference to the ethmoidal nerve and innervation of nasal and cerebral blood vessels. ANIMALS: 12 adult sheep used for monolateral (n = 7) or bilateral (n = 5) ethmoidal neurectomy; 2 sheep used for angiography (1 live sheep for digital subtraction angiography, 1 embalmed cadaver for injection studies); and 5 embalmed cadavers, 4 frozen specimens, and 2 dry skulls used for dissection, x-rays, and computed tomographic (CT) or magnetic resonance (MR) scans. PROCEDURE: Transverse (coronal) MR scans, transverse, sagittal, and dorsal CT scans, radiography, angiography, photographic images, and dissections of embalmed material were used to study the topographic anatomy of the temporal and pterygopalatine fossae of the head. RESULTS: Images were stored, then compared with photographs of frozen sections from the same or a similar specimen to plan a surgical approach to the ethmoidal nerve. Mono- and bilateral experimental ethmoidal neurectomies were performed, allowing characterization of a safe and reliable method. The series of pterygopalatine ganglia typical of this species was localized, dissected, and analyzed for topographic relations. CONCLUSIONS: From the results, a new approach to the efferent branches of the pterygopalatine ganglia (ethmoidal nerve) for experimental parasympathectomy of the cerebral and nasal circle is proposed. This experimental approach could be used for studies involving thermoregulation of the face, and in experimental control of blood flow in the nasal cavity and rostral part of the brain.

Localization accuracy of AC-PC line and functional pallidal target using BRW stereotactic implementation system and axial CT scanning. An experimental study.

BACKGROUND: Ventriculography is still considered an unavoidable step for functional target localization, even though this method is invasive and requires stereotactic rooms, orthogonal frames, and parallax-free X-ray equipment. In this experimental study, the authors investigated the feasibility of performing stereotactic lesions using a conventional, widely employed frame, such as the Brown-Roberts-Wells (BRW) apparatus, and computerized axial tomography (CAT) imaging. METHODS: Five ex vivo models consisting of cadaveric brains enclose in a plastic shell were fixed in a BRW frame. A simple BRW implementation was used to ensure more symmetrical placement of the basal ring. Two-millimeter plastic balls were inserted at the level of the anterior (AC) and posterior commissures (PC) and at the target in the pallidus. Their final position was measured on the anatomical specimens and compared with Schaltenbrand Atlas maps. RESULTS: The error in estimating the length of the intercommissural line ranged from 0.5 mm to 2.0 mm, with a maximum backward angulation of four degrees in predicting the AC-PC plane. Upon dissection, in four out of five cases, the balls were found within the area of the pallidus defined by Laitinen for posteroventral pallidotomy. CONCLUSIONS: The authors conclude that anatomical identification of the AC-PC line and the pallidus target, using the BRW stereotactic system and CAT axial images alone offers sufficient accuracy. They suggest that functional neurosurgery for movement disorders could be safely and successfully carried out without ventriculography if neurophysiological monitoring is also employed.

Aphasia in left-handers. Comparison of aphasia profiles and language recovery in non-right-handed and matched right-handed patients.

The present retrospective analysis reports two studies. In Study 1, clinical aspects of aphasia are compared in right-handed (RH) and non-right-handed (NRH) patients; in Study 2, recovery from aphasia is compared in RH and NRH aphasic patients with a minimum of 5 months of daily language rehabilitation. From a continuous series of 1200 brain-damaged subjects, 24 NRH patients with a vascular lesion documented by computerized tomography were selected. In 19 cases the lesion was in the left hemisphere and in 5 cases in the right hemisphere. For 14 NRH patients, a RH subject with similar lesion, matched for age, education, length of illness, etiology (ischemic vs. hemorrhagic), and, when possible, sex was found. Presence and type of aphasia were compared in the two patients of the same pair and were found similar except for Pair 14; the RH subject had global aphasia and the NRH had conduction-like aphasia. Fifteen NRH patients were rehabilitated and reexamined at least 5 months after the first examination. Recovery of the 12 patients with a left-hemisphere lesion was compared with recovery of a group of RH subjects and no significant differences were found. Recovery of the three patients with right-hemisphere lesions is described. It is concluded that differences in type of aphasia and recovery between RHs and NRHs have been overemphasized in the past and must be reconsidered.

Aphasia arising from purely deep lesions.

In this study we investigated the relationship between deep-seated lesions of the left hemisphere and the aphasic disturbances. Thirty-seven vascular patients with CT-scan, language and neuropsychological examination carried out between 15 and 60 days post-onset were studied. Presence and frequency of apraxic disorders and acalculia are also reported. A consistent relationship between the site of the lesion and the pattern of aphasic disturbances could not be established. The most striking finding was a dissociation between oral and written expression, the latter being disproportionately impaired in a number of subjects.

Facial pain associated with hydrocephalus by aqueduct stenosis. Complete recovery after ventriculo-atrial shunt. Case report.

The Authors describe the case of a patient with facial pain associated with hydrocephalus which had a complete recovery after the placement of a ventriculo-atrial shunt. The possible pathological basis of this symptom are discussed.

[Radiotherapy of brain tumors in childhood]. / Radioterapia dei tumori cerebrali nell'infanzia.

External radiotherapy with high energy photons in children's brain tumors improves results of surgical treatment according to their histology. Radiotherapy treatment is a decisive factor in survival time and quality of life. Undifferentiated tumors with high radiosensitivity are treated when radiotherapy is the only means for recovery; tumors presenting histologically low malignancy in which effective radiotherapy treatment is uncertain and the risk of radiotherapy damage is the predominant factor. Radiotherapists who treat children's brains which in many cases are not yet totally myelinized , must have good technical ability. Literature and personal experience show that in medulloblastomas irradiation of the entire central nervous system associated with chemotherapy gives a survival time of 5 years in 50% of the cases; in glioblastomas and anaplastic astrocytomas, fortunately rare in children, results are poor; in brainstem tumors the association of the extracranial shunt to radiotherapy has improved results of survival time at 5 years to 50%. A good quality of life is frequent and radiological effects are rare. It is clear that radiotherapy has reached its maximum. Progress is still to be made thanks to discoveries of more effective radiosensitizer or radioprotector compounds.

[Neuroradiology in cerebral gliomas]. / Neuroradiologia dei gliomi cerebrali.

CT Scan has greatly helped preoperative diagnosis in brain tumors. CT Scan alterations are found in about 95% of brain tumors and the most modern instruments can pick-up even small alterations, locate them precisely and, in 80% to 90% of the cases can give their exact extension. But precise CT-scan diagnosis in brain tumors can be done in only 80% of the cases when in a supratentorial site; about 90% in infratentorial localizations. Differential diagnosis difficulties occur with metastasis, abscesses, infarction, meningiomas, and vessel malformations. Angiography does not always solve these diagnostic problems left uncovered by CT Scan and not infrequently surgical proof is necessary.

[Radiotherapy of primary and secondary spinal tumors]. / La radioterapia dei tumori spinali primitivi e metastatici.

Radiotherapy in primary and metastatic spinal cord tumors following surgical treatment, or even without surgery, is very effective. The Authors analyse the different types of spinal tumors giving the survival time for every one. The results are related to the possible medullary damage before radiotherapy and to the sensibility of the tumor itself. The Authors emphasize the importance of two factors: 1) early diagnosis (myelography); 2) immediate therapy (high dose steroids, surgical decompression and/or radiotherapy).