Biomedical subjects

A Nabavi

Publications and source records attributed to A Nabavi.

23 records · Page 2Linked to original sources

PubMed1998

Intracranial cavernomas: indications for and results of surgery.

Between April 1991 and April 1997, 46 patients were treated in our department presenting with intracranial cavernomas. Initial symptoms were focal seizures, bleeding episodes, and/or headaches. Mean age was 41 year (range 9 to 68 years). There were 24 female and 22 male patients. Computed tomography and magnetic resonance imaging were performed in order to establish the diagnosis, angiography was only indicated when the hemorrhaged area was so close to the subarachnoid space in the vicinity of the basal cisterns that an aneurysm had to be ruled out. Aggressive indication for surgery also in brainstem cavernomas was based on the natural history of the lesion, since the majority of patients presenting with intracranial bleeding had suffered several (up to six) episodes of previous hemorrhages. Patients' clinical status upon admission and accessibility of the cavernoma were taken into account for planning the operation. The operative planning and approach were greatly facilitated by using a neuronavigational device and intraoperative electrophysiological monitoring particularly in cavernomas located in the brainstem, thalamus, and medulla oblongata. Surgical removal of the lesions resulted in a new permanent neurological deficit only in two patients (4%). These data show that patients benefit from modern neurosurgical techniques in contrast to conservative approach in this disease of rather prolonged natural course.

Adolescent↗

PubMed1996

[Perimesencephalic subarachnoid hemorrhage--an independent clinical picture of non-aneurysmatic subarachnoid hemorrhage with a benign course].

Two hundred seventy-three Patients with acute SAH were treated within the last 46 months (1.4.1991 to 31.1.1995). Diagnosis was made upon visible SAH on CT-scans or bloody spinal tap regardless of a negative CT-scan. These patients harbored 194 aneurysms, 25 AVM and cavernomas. Within the same time-period we treated 27 Patients without SAH but harboring vascular malformations (17 aneurysms, 10 AVM and cavernomas). In 30 patients (11%) no bleeding source was detectable. Fourteen of these patients (5.1%) had blood concentrated within the perimesencephalic cisterns on the CT-scans. On admission all of these 14 patients (8 men, 6 female, aged 30 to 63 years) were awake and without mentionable neurological deficit, equalling Hunt & Hess grade 1 (11 patients) and 2 (3 patients). Neither the initial nor control angiography revealed a vascular malformation as a bleeding source. MRI-scans performed for 11 patients did not reveal further etiological clues. During a follow-up interval of 3 to 48 months, none of these patients suffered a rebleeding. Vasospasm was not or only slightly present, no ischemia leading to neurological deficit. GOS reached 5 and Karnofsky-scale was 100 for all of these patients. We conclude that the perimesencephalic SAH is a homogeneous entity with a different natural course than the common aneurysmatic SAH. Probably leakage within the capillary or venous circulation causes this form of SAH with a benign clinical course. Further experience is required to determine whether control angiography is mandatory in these patents with a distinct CT appearance.

Adult↗

PubMed1995

[Neuronavigation. Computer-assisted surgery in neurosurgery].

Computers in Neurosurgery were limited to diagnostics, planning stereotactic procedures, Radiosurgery and Radiation therapy. The possibility of intra-operative localisation only evolved since the mid 80's with the advent of more powerful computers. The computer adds more precision to microneurosurgical procedures, allowing neuronavigation in interaction with the computer. Diverse neuronavigationsystems are described in the literature [7-9, 11, 13]. We are working with the "ISG Viewing Wand" since april 1994. 113 operations were planed and executed aided by this system. We report on our experiences, the advantages and limitations of this system.

Adult↗

PubMed1993

[Muscle anomalies of the upper extremity as an atavistic cause of peripheral nerve disorder].

We report on 2 patients with anomalous muscles of the upper extremity causing symptoms of peripheral nerve entrapment. Our first case clinically showed a lesion of the R. dorsalis manus of nervus ulnaris produced by an accessory muscle belly at the dorsum of the hand to be identified as an extensor indicis brevis muscle. The second case presented a carpal-tunnel-syndrome, tunnel into the palm. Phylogenetically and ontogenetically these muscles are classified as atavistic. We demonstrate the homologies of the upper extremity of fishes, amphibians, reptiles, lower mammals and man, which show an upward migration of the muscle masses from the hand to the forearm. By that means the upper extremity gains additionally to the power of the reptiles paw the functionality and free motility of the human hand.

Adult↗

PubMedDate not supplied

Three-dimensional optical flow method for measurement of volumetric brain deformation from intraoperative MR images.

A three-dimensional optical flow method to measure volumetric brain deformation from sequential intraoperative MR images and preliminary clinical results from five cases are reported. Intraoperative MR images were scanned before and after dura opening, twice during tumor resection, and immediately after dura closure. The maximum cortical surface shift measured was 11 mm and subsurface shift was 4 mm. The computed deformation field was most satisfactory when the skin was segmented and removed from the images before the optical flow computation.

Adult↗