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Biomedical subjects

M I Hariz

Publications and source records attributed to M I Hariz.

14 recordsLinked to original sources
PubMed1992

Ventroposterolateral pallidotomy can abolish all parkinsonian symptoms.

Stereotactic ventroposterolateral pallidotomy in 46 parkinsonian patients resulted in a complete or almost complete and long-lasting relief of rigidity and hypokinesia in 91% of the patients. Good tremor effect was obtained in 80% of them. The L-dopa-induced dyskinesias, gait and speech improved in most patients. Complications were observed in 7 cases after 51 pallidotomies, i.e. 14% (partial homonymous hemianopia in 6 and transient dysphasia and facial weakness in 1). We believe that the good effect of surgery is based on interruption of some striopallidal or subthalamopallidal pathways.

Dystonia↗
PubMed1992

Leksell's posteroventral pallidotomy in the treatment of Parkinson's disease.

Between 1985 and 1990, the authors performed stereotactic posteroventral pallidotomies on 38 patients with Parkinson's disease whose main complaint was hypokinesia. Upon re-examination 2 to 71 months after surgery (mean 28 months), complete or almost complete relief of rigidity and hypokinesia was observed in 92% of the patients. Of the 32 patients who before surgery also suffered from tremor, 26 (81%) had complete or almost complete relief of tremor. The L-dopa-induced dyskinesias and muscle pain had greatly improved or disappeared in most patients, and gait and speech volume also showed remarkable improvement. Complications were observed in seven patients: six had a permanent partial homonymous hemianopsia (one also had transient dysphasia and facial weakness) and one developed transitory hemiparesis 1 week after pallidotomy. The results presented here confirm the 1960 findings of Svennilson, et al., that parkinsonian tremor, rigidity, and hypokinesia can be effectively abolished by posteroventral pallidotomy, an approach developed in 1956 and 1957 by Lars Leksell. The positive effect of posteroventral pallidotomy is believed to be based on the interruption of some striopallidal or subthalamopallidal pathways, which results in disinhibition of medial pallidal activity necessary for movement control.

Adult↗
PubMed1991

Relation between sensory disturbance and outcome after retrogasserian glycerol rhizotomy.

The relation between postoperative sensory deterioration and surgical outcome in 54 patients treated by retrogasserian glycerol rhizotomy for trigeminal neuralgia was studied. The facial sensibility was assessed one day and three months postoperatively. Thresholds for perception and pain were determined quantitatively using transcutaneous electrical stimulation and clinically by light touch and pinprick tests. At a follow-up one year after surgery there was no significant difference in pain relief between patients who did show and patients who did not show sensory deterioration at the one day or three months evaluations. Nevertheless, there was a tendency for higher recurrence rate in patients with mild or no sensory disturbance.

Aged↗
PubMed1991

Clinical study on the accuracy of the Laitinen CT-guidance system in functional stereotactic neurosurgery.

The accuracy, reproducibility and reliability of CT-guided functional stereotaxis using Laitinen's Stereoadapter were assessed in 19 patients who underwent 14 thalamotomies and 5 pallidotomies for the treatment of essential tremor or Parkinson's disease. The coordinates of the target were obtained from a CT study with the Stereoadapter. At surgery, the Stereoadapter was remounted to the patient's head and the CT coordinates were transferred to Laitinen's Stereoguide without ventriculography. 3-12 months after surgery, a postoperative CT study with Stereoadapter was done. The coordinates of the stereotactic lesion were compared to the preoperative target coordinates. A new similar target was simulated on the postoperative CT study and its coordinates were compared to those of the preoperative target. The coordinates of the lesion versus preoperative target showed a maximal difference of 3.5 mm for the lateral (x-) coordinate, 3.5 mm for the anteroposterior (y-) coordinate, and 3.75 mm for the height (z-) coordinate. The differences were statistically significantly only for the x-coordinate: The lesions lay 1.25 mm, on the average, medial to the preoperative target. This medial displacement of the lesions was presumably due to a 10% inborn magnification error of the CT picture for the lateral direction. The maximal differences between the coordinates of the 'new' simulated target on the postoperative CT and those of the preoperative target were 2.5 mm for the x-, 2.25 mm for the y- and 3.75 mm for the z-coordinates. The differences were not statistically significant.

Adult↗
PubMed1991

Selectivity of retrogasserian glycerol rhizotomy in the treatment of trigeminal neuralgia.

The possibility of obtaining a selective effect on different trigeminal branches by glycerol rhizotomy was studied in the treatment of trigeminal neuralgia. Transcutaneous electrical stimulation was used to quantify sensory impairment. An attempt was made to direct the neurotoxic effect by maintaining the patient's head in different positions during and after glycerol injection. The amount of glycerol injected varied according to the estimated size of the trigeminal cistern and/or to which branch that was involved. The study demonstrated a good selective effect on the ophthalmic branch, less selective on the maxillary, and a poorly selective effect on the mandibular branch. However, the clinical result following glycerol rhizotomy was equal regardless of the affected trigeminal branch.

Aged↗
PubMed1990

A non-invasive method for fractionated stereotactic irradiation of brain tumors with linear accelerator.

A new technique for fractionated stereotactic irradiation of intracranial lesions is described. The treatment is based on a versatile, non-invasive interface for stereotactic localization of the brain target imaged by computed tomography (CT), angiography or magnetic resonance tomography (MRT), and subsequent repetitive stereotactic irradiation of the target using a linear accelerator. The fractionation of the stereotactic irradiation was intended to meet the requirements of the basic principles of radiobiology. The radiophysical evaluation using phantoms, and the clinical results in a small number of patients, demonstrated a good reproducibility between repeated positionings of the target in the isocenter of the accelerator, and a high degree of accuracy in the treatment of brain lesions.

Adult↗
PubMed1990

Correlation between clinical outcome and size and site of the lesion in computed tomography guided thalamotomy and pallidotomy.

Fourteen thalamotomies and five pallidotomies were performed in 19 patients with hereditary intention tremor or Parkinson's disease. The target coordinates were determined by a stereotactic computed tomography study using the Laitinen noninvasive stereoadapter. Surgery was done without ventriculography. The patients were assessed 3-12 months later. In a postoperative stereotactic computed tomography study, the positions of the thalamic and pallidal targets were marked, and the coordinates of the center of the lesion were measured in relation to these targets. The volume of the lesion was calculated. In 3 thalamic lesion patients, no lesion could be visualized. The size of the eleven visible thalamic lesions ranged from 4 to 75 mm3 (mean 26), and the size of the 5 pallidal lesions ranged from 28 to 150 mm3 (mean 67). On the average, the center of the lesion was 1.4 mm medial to the position of the anatomical target (p less than 0.002). Neither size nor site of the lesion correlated with the clinical outcome.

Adult↗
PubMed1990

Percutaneous stereotactic brain tumour biopsy and cyst aspiration with a non-invasive frame.

A non-invasive Stereoadapter was used for stereotactic CT-guided percutaneous brain biopsy in 18 patients with 16 solid tumours and four cysts. The Stereoadapter was mounted on the patient's head using ear plugs and a nasion support. After the CT study, the Stereoadapter was detached. The target was simulated on a phantom base and a probe carrier attached to the Stereoadapter. For surgery, the Stereoadapter with the probe carrier was remounted to the patient's head. Local anaesthesia was mainly used. Tissue samples were aspirated with a 2 mm diameter Sedan-Nashold biopsy cannula, introduced through a twist drill hole. Conclusive histological/cytological diagnosis was obtained in 16 of the 20 lesions. The new method proved to be reliable and quick. Since the imaging study and the surgery could be separated in time and place, the biopsy procedure was less time-consuming than previous methods of stereotactic biopsy using an invasive frame.

Adolescent↗
PubMed1990

A comparative study on ventriculographic and computerized tomography-guided determinations of brain targets in functional stereotaxis.

Thalamic, pallidal, and hypothalamic targets were determined in 16 patients by a stereotactic computerized tomography (CT) study using a noninvasive technique with Laitinen's Stereoadapter. At surgery, the Stereoadapter was remounted to the head and the stereotactic CT coordinates were transferred to the Stereoguide without radiography. Air ventriculography was then carried out. The positions of the anterior and posterior commissures (AC and PC), the length of the intercommissural (IC) line, the width of the third ventricle, and the stereotactic coordinates of the target were measured on the ventriculograms and compared to the stereotactic CT measurements. The study showed that the width of the third ventricle was significantly larger on the ventriculograms than on the stereotactic CT scans, whereas the length of the IC line was not significantly different. The differences in the coordinates of the target and of the AC and PC were statistically significant only for the anteroposterior (y) coordinate. Both commissures as well as the surgical target lay, on average, 1.0 mm more anteriorly on the ventriculograms than on the stereotactic CT study. It is concluded that air ventriculography may cause slight anterior displacement of the midbrain structures. The surgical coordinates of the targets based on the stereotactic CT study with the Stereoadapter were on average as accurate as those obtained with ventriculography; therefore, ventriculography may become superfluous in functional stereotaxis.

Adolescent↗
PubMed1987

Stereotactic localization of small subcortical brain tumors for open surgery.

A noninvasive, computed tomography (CT) stereoadapter was used for stereotactic localization of small brain tumors in 16 patients scheduled for open surgery. The stereotactic CT study was carried out 1 day to 3 months before surgery. On the day of surgery, the adapter was remounted on the patient's head. The tumor in relation to the adapter, as shown on the CT study, was drawn on the scalp of the patient. The tumor could be found and removed through a small bone opening and a minimal cortical incision.

Adolescent↗
PubMed1987

Multi-purpose stereoadapter.

A noninvasive adapter for CT-, MRI- and angiography-guided stereotaxis had originally been developed for morphological (tumor biopsy) surgery. Because of its high accuracy it has also been used for functional stereotaxis (e.g., thalamotomy, cingulotomy, hypothalamotomy, dentatotomy) and for external stereotactic irradiation of brain tumors and arteriovenous malformations with a conventional linear accelerator. Additionally, it has been used for locating subcortical brain tumors for open surgery. Recently, the adapter, supplied with a phantom base, has been used for percutaneous tumor biopsy and ventriculostomy without a stereotactic frame.

Equipment Design↗
PubMed1986

Reproducibility of repeated mountings of a noninvasive CT/MRI stereoadapter.

The reproducibility of a noninvasive computed tomography (CT)/magnetic resonance imaging stereoadapter was tested on 12 healthy volunteers. The adapter was easy to mount and detach without discomfort. Two repeated mountings of the adapter showed a good reproducibility in relation to the scalp. When extrapolated to a hypothetical target in the right thalamus, the mean differences between the two mountings were 0.07 mm in the lateral, 0.16 mm in the anteroposterior and 0.17 mm in the height coordinates. This high degree of reproducibility seems to permit a safe CT-guided functional stereotaxis, where the preoperative CT scanning can take place on one day and the surgery may be performed on any other suitable day.

Adult↗
PubMed1986

[Pre- and postoperative quantitative measures of facial sensitivity in tic douloureux].

Electrical stimulation was used for quantitative assessment of facial sensibility before, during and after percutaneous electrocoagulation of the Gasserian ganglion in 19 patients with tic douloureux. A portable stimulator was of a constant current type, which generated rectangular monophasic pulses of 0,2 ms in length and 100 Hz in frequency. The bipolar electrode consisted of saline-soaked felt discs with a surface of 1 cm2 and an interpolar distance of 1 cm. The thresholds for perception and pain were measured over six regions of each side of the face. Additionally, maximal pain tolerance was measured in the painful area and its corresponding healthy area. Shortlasting intravenous anesthesia with Brietal was given before each electrocoagulation. As soon as the patient began to react to speech, the threshold for pain was measured in the painful and the corresponding healthy area. Preoperatively, the measurements showed that the average threshold for perception was 2,5 mA and for pain 3,5 mA. The average maximal pain tolerance was 10,8 mA. There were no differences between the painful and the healthy sides. Electrocoagulations were stopped when the thresholds for pain in the trigger area had become twice as high as that on the contralateral side. The postoperative measurements showed that the average thresholds for perception and pain had doubled, measuring 4,8 and 8,0 mA, respectively. The average pain tolerance had risen from 10,8 to 22,5 mA. A marked rise of both thresholds was also seen in the ipsilateral areas adjacent to the trigger zone. There was good correlation between a heavy sensory deficit and a favourable clinical result.(ABSTRACT TRUNCATED AT 250 WORDS)

Face↗