Freezing of gait before the introduction of levodopa

Freezing of gait (FOG) occurs in over half of patients with advanced Parkinson's disease. It is characterised by sudden, brief episodes of inability to produce effective forward stepping that typically occur upon gait initiation or during turning while walking. FOG can be subdivided into three clinically distinguishable phenotypes. The two most common forms, which can be seen both when patients are ‘on’ or ‘off’ their dopaminergic medication, are shuffling forward with very small steps and trembling in place without effective forward motion. The third and most severe, but also least common, form of FOG is complete akinesia. FOG is associated with increased disease severity and with prolonged levodopa treatment (although the latter could also be explained by greater disease severity). FOG is generally responsive to dopaminergic medication, and episodes are therefore more frequent and of longer duration when dopaminergic medication has worn off. Paradoxically, our general impression is that FOG is nowadays more common than before the introduction of levodopa. In a brief report published in 2011, Pedro J Garcia-Ruiz also reached this conclusion, but he did not perform a systematic assessment of all resources. MPTP-induced parkinsonism: an historical case seriesIn 1982, seven young adults developed severe and irreversible parkinsonism shortly after they injected themselves with a new synthetic heroin.1 Sample analyses revealed that this synthetic heroin consisted of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP),2 a potent neurotoxin targeting neurons within the substantia nigra.3 Full-Text PDF Freezing of gait: a practical approach to managementFreezing of gait is a common and disabling symptom in patients with parkinsonism, characterised by sudden and brief episodes of inability to produce effective forward stepping. These episodes typically occur during gait initiation or turning. Treatment is important because freezing of gait is a major risk factor for falls in parkinsonism, and a source of disability to patients. Various treatment approaches exist, including pharmacological and surgical options, as well as physiotherapy and occupational therapy, but evidence is inconclusive for many approaches, and clear treatment protocols are not available. Full-Text PDF Freezing of gait and levodopaIn their Historical Insight, Peter Koehler and colleagues1 propose that freezing of gait (FOG) in patients with advanced Parkinson's disease is the result of chronic long-term levodopa use. Furthermore, they notice that, if FOG was present in the pre-levodopa era, it expressed itself as akinetic, not as the shuffling and trembling subtypes seen mostly nowadays. Therefore, they conclude that the high-frequency oscillatory features of FOG are probably induced by levodopa. Although we appreciate this thought-provoking hypothesis, we would like to present some observations that refute it. Full-Text PDF