ABSTRACT
MRI was used to investigate 100 patients with hemifacial spasm, using 3D-FT T2-weighted (CISS) and contrast-enhanced 3D-FT T1-weighted (turbo-FLASH) sequences in all cases. MR angiography was performed in 54 patients, using 3D-MT FISP images. Decompression of the facial nerve through a retromastoid craniotomy was performed in all patients. Hemifacial spasm caused by tumours in the cerebellopontine angle was not included. Vascular contact with the facial nerve root-exit zone or at the internal auditory canal was present in 96 of 100 patients with hemifacial spasm. The vessel responsible was the vertebral artery (VA) in 18 cases, the posterior inferior cerebellar artery (PICA) in 23, the anterior inferior cerebellar artery (AICA) in 22, the VA and PICA in 24, VA and AICA in 3, PICA and AICA in 1, VA, PICA and AICA in 4, and a vein in 1 case. CISS images showed compressive vascular loops better than contrast-enhanced turbo-FLASH images alone. The sensitivity of MRI was high, since only one false-negative case was found among the 100 patients who underwent surgery.
Subject(s)
Facial Muscles/pathology , Magnetic Resonance Angiography/methods , Magnetic Resonance Imaging/methods , Spasm/diagnosis , Spasm/surgery , Adult , Aged , Aged, 80 and over , Face/blood supply , Female , Humans , Male , Middle Aged , Spasm/physiopathologyABSTRACT
This study of the topographic distribution of tumoral and pseudotumoral lesions of the proximal femur shows that certain lesions have a preferential site, for example osteoid osteoma affects the internal cortex of the neck and diaphysis or the intertrochanteric zone; chondroblastoma occurs in zones of epiphyseal ossification of the head; fibrous dysplasia affects the femoral neck, while sparing the epiphyseal femoral head and trochanters. The island of osteosclerosis is situated, at least partially, in the support fan; so-called physiological cysts are situated on or above the midline of the neck and below the basicapital line. Osteolytic or mixed metastases preferentially involve Ward's triangle in the femoral neck and the intertrochanteric region. The sites of these lesions therefore appears to depend on the bony architecture which, in turn, is dependent on mechanical stresses. However, this purely morphological study fails to demonstrate whether mechanical stresses influence the development of these lesions.
