Midbrain tremor and hypertrophic olivary degeneration after pontine hemorrhage.

A severe rest tremor arose in a patient's right arm 9 months after a pontine tegmental hemorrhage. Magnetic resonance studies at 4 and 10 months showed residual hemosiderin in the pons and increasing hypertrophic olivary degeneration (HOD) affecting primarily the left olive. The tremor was refractory to pharmacotherapy (clonazepam, propranolol, and levodopa), but was reduced after implantation of a thalamic stimulator device. Although pontine hemorrhage is among several common causes of HOD, it has not previously been appreciated as a cause of midbrain ("rubral") tremor. A disynaptic dentatorubroolivary tract associated with tremor and monosynaptic dentatoolivary tract associated with HOD may both be components of the rubroolivocerebellorubral loop implicated in midbrain tremor. Their proximity makes the combination of tremor and HOD after pontine tegmental damage plausible and even likely.

Sandostatin LAR in acromegalic patients: long-term treatment.

We have evaluated the long term effects and safety of Sandostatin LAR, a long acting formulation of octreotide, during 18 subsequent injections given every fourth week to 14 octreotide-sensitive acromegalic patients. The dosages (20, 30, or 40 mg) were adjusted according to GH response, side-effects, or symptom relief and assessed on day 28 after each injection. We found a stable and consistent suppression of GH and insulin-like growth factor (IGF-I) during the entire study period. Daily mean GH levels were suppressed below 2 micrograms/L in 9, to between 2-5 micrograms/L in 3, and to between 5-10 micrograms/L in 2 patients. The corresponding IGF-I values were suppressed to below 500 micrograms/L in 9 patients and to between 500-1000 micrograms/L in the remaining 5 patients. Increasing the dosage of Sandostatin LAR from 20 to 30 mg had no obvious additional effect on GH suppression, but provided a further decrease in IGF-I levels. Forty milligrams of the drug had no additional effect on GH or IGF-I compared to 30 mg. Acromegalic signs and symptoms improved during treatment. Although the fluctuations of daily mean octreotide levels were high, dosage increments caused an increase in the average serum concentration in the individual patient. Pituitary tumor size reduction was seen in all previously untreated patients (n = 4). We found only minor changes in glucose metabolism (oral glucose tolerance test and hemoglobin A1C) during treatment, but no biologically relevant changes in thyroid function (TSH, T3, and free T4). One patient developed asymptomatic gallstones, and another acquired vitamin B12 deficiency during treatment. The drug is well tolerated during long term treatment. Sandostatin LAR may well be the future medical treatment of choice for acromegalic patients.

MR imaging of pituitary region lesions with gadodiamide injection.

Twelve patients with known or suspected pituitary lesions underwent MR imaging with gadodiamide injection at a dose of 0.1 (n = 5) or 0.3 (n = 7) mM/kg. Six of the patients were also studied with 0.1 mM/kg gadopentetate dimeglumine. Consistent with previous reports gadodiamide injection was found to be a safe and effective contrast medium for MR imaging of the pituitary region. No additional diagnostic information was obtained using 0.3 mM/kg gadodiamide injection compared to 0.1 mM/kg gadopentate dimeglumine in the same patients. The high dose (0.3 mM/kg) gadodiamide injection in 7 patients did not shorten the T2 value sufficiently to overwhelm the T1 shortening and leave pathologic lesions hypointense compared to precontrast studies. With the comparable relaxivities of gadodiamide injection and gadopentetate dimeglumine, similarities in results have to be expected when using these media for MR image enhancement.