Primary progressive freezing gait.

Freezing gait is an incapacitating symptom often observed in patients with Parkinson's disease. It has been less frequently described in association with multi-infarct state, multisystem atrophies, and normotensive hydrocephalus. In our movement disorder clinic, we have diagnosed (and followed up to 3 years; median, 16 months), 18 patients in whom progressive freezing gait was the sole neurological dysfunction. These 15 men and 3 women (aged 60-82 years; 74 +/- 6) were subjected to an extensive neurological workup that included clinical evaluation, videotaping for grading of gait disability, comprehensive blood and cerebrospinal fluid (CSF) analysis, and brain computed tomography (CT) and magnetic resonance imaging (MRI). Mean disease duration was 2.5 +/- 1.9 years (range, 0.5-6). Neurological examination disclosed freezing gait, often associated with varying degrees of postural instability. The degree of freezing gait ranged from sudden motor blocks only when confronted with obstacles to severe disability with total inability to start walking requiring a walker, massive assistance, or a wheelchair. However, patients could mimic gait movements with absolutely no freezing when seated or lying prone, and most of them could overcome arrests by the "walking-over-lines" maneuver. Otherwise, neurological examination was normal with no signs of bradykinesia, rigidity, or tremor. Blood chemistry and CSF analysis were normal. Brain CT and MRI were normal or showed mild cortical atrophy in 12 and putative lacunes in 6 patients. Therapy with levodopa or dopamine agonists was ineffective. During the follow-up period, a gradual progression of the freezing gait was observed. However, it remained unaccompanied by any other neurological findings.(ABSTRACT TRUNCATED AT 250 WORDS)