Impact of thalamic deep brain stimulation on disability and health-related quality of life in patients with essential tremor.

OBJECTIVES: To evaluate the impact of thalamic deep brain stimulation (DBS) on disability and health-related quality of life in patients with essential tremor. METHODS: Twenty seven consecutive patients were evaluated prospectively, before surgery and at a mean of 12 months (range 6-26) after thalamic DBS. Assessment tools included the Fahn-Tolosa-Marìn tremor rating scale (TRS), activities of daily living (ADL) taxonomy, Nottingham health profile (NHP) and the visual analogue scale (VAS) for measuring impact of disease on life. Additional information on the side effects of, and expectations from surgery was obtained by interview. RESULTS: Thalamic DBS improved the ability of the patients in eating, drinking, writing, home maintenance, hobbies, and participation in society. Activities of daily life requiring bimanual skills were less improved. The emotional condition of the patients was positively affected and the negative impact of the disease on life as a whole, and on social life was decreased. Seventy per cent of the patients considered that the surgical treatment met their expectations. CONCLUSIONS: After thalamic DBS, health-related quality of life including disability in ADL and social life were improved in patients with essential tremor.

Assessment of ability/disability in patients treated with chronic thalamic stimulation for tremor.

Chronic thalamic stimulation (CTS) has a documented good effect on tremor in patients with Parkinson's disease (PD) and essential tremor (ET). This study evaluates whether the alleviation of impairment, i.e., tremor, translates into improvement of the patient's ability in performing instrumental activities of daily living (IADL). Thirteen patients were assessed with an occupational therapy tool called Assessment of Motor and Process Skills (AMPS). This observation-based scale rates the patient's motor and process skills needed to perform a given task. The evaluations were done at a mean of 13 months after surgery in the patient's home, and included assessments of IADL with the CTS activated and switched off, respectively. The results showed that most patients improved to variable degrees in their IADL ability when the thalamic stimulation was on. The improvement was more marked in patients operated on for tremor of their dominant hand. The improvement concerned mainly the skill items related to the patients' abilities of coordination, calibration, endurance, and accommodation during IADL task performance. The authors concluded that for some patients with tremor, CTS can improve independence in domestic activities of daily living.

Thalamic stereotaxis for chronic pain: ablative lesion or stimulation?

Twenty-five patients underwent 33 stereotactic procedures on the thalamus for the treatment of persistent pain of benign or malignant origin. There were 19 ablative and 14 stimulation procedures. The thalamic targets were the centrum medianum (CM), the pulvinar, the nucleus ventralis posteromedialis and/or the nucleus ventralis posterolateralis. Ablative surgery was successful in 52.6% of the procedures, and chronic stimulation in 66%. Stimulation in the ventroposterior group of the thalamus was most effective for peripheral deafferentation pain while ablative stereotaxis on the CM may be more appropriate for patients with central pain or cancer pain. ¿¿

Air-ventriculography provokes an anterior displacement of the third ventricle during functional stereotactic procedures.

The width of the third ventricle, the length of the anterior commissure-posterior commissure line (AC-PC line), the spatial position of the midplane of the third ventricle, and the co-ordinates of the AC, the PC, and of 17 brain targets in the thalamus, hypothalamus and pallidum, were assessed on a pre-operative stereotactic computed-tomography (CT) study and compared to measurements on intra-operative air-ventriculography, using a non-invasive relocatable stereotactic frame. There were no significant differences in the length of the AC-PC line, in the position of the midsagittal plane of the third ventricle, or in the vertical or lateral co-ordinates of the AC, the PC and the cerebral targets, between measurements on CT and on air-ventriculography. However, the width of the third ventricle was significantly larger, and the spatial positions of both AC and PC were significantly more anterior on air-ventriculography than on the CT study. This anterior dislocation of the commissures was presumably due to the insufflation of air into the ventricles of patients being in the supine position during surgery.

Retrogasserian glycerol rhizotomy and its selectivity in the treatment of trigeminal neuralgia.

In the treatment of trigeminal neuralgia, the possibility of obtaining a selective effect on different trigeminal branches by glycerol rhizotomy was studied. Transcutaneous electrical stimulation was used to quantify sensory impairment. An attempt was made to obtain a localized neurotoxic effect of the glycerol on the different trigeminal branches by keeping the patient's head in different positions during and for one hour 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 highly selective effect on the ophthalmic branch, less selective on the maxillary, and a low selective effect on the mandibular branch. However, the clinical results were equal regardless of the affected trigeminal division.

Clinical evaluation of computed tomography-guided versus ventriculography-guided thalamotomy for movement disorders.

38 patients with Parkinsonian or essential tremor who underwent thalamotomy based on ventriculographic coordinates were compared to 23 patients whose thalamotomy was performed on the basis of computed tomography (CT)-derived target coordinates. The comparison between the two groups concerned the age, sex, duration of disease, target side, intra-operative target correction, duration of postoperative stay in hospital, transient side-effects, permanent complication, and tremor alleviation. The study showed that the surgical results in terms of tremor control were the same in the two groups. However, the percentage of post-operative transient side-effects was higher and the duration of stay in hospital was longer for the ventriculographic patients than for the CT patients.

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.