The word “ freeze ” did evoke sufficient reverberations in my hippocampal circuitry instantly to yield 10 related facts : cryotherapy and cryosurgery , frostbite , accidental hypothermia , induced hypothermia , Raynaud ’ s phenomenon , rigors , frozen section and freezing of gait . Being fond of neurophysiology , I was compelled to add to the list TRPM8 ( transient receptor potential melastatin ) channels , which are crucial for perception of cold sensation ( David Julius and Ardem Patapoitian received the 2021 Nobel prize for Physiology / Medicine for their discovery ) and the notorious patient-hated cold allodynia , a common complication of chemotherapeutic agents like oxaliplatin . Among these topics , the phenomenon of freezing of gait has been of much interest to me as a neurologist . Of course , the exercise of going through the Quiz Ten instantly reversed my state of gloom and triggered some exciting memories .
Having been a clinician and teacher for almost five decades , I have been privileged to see many patients with the troublesome symptom of freezing of gait ( FOG ). I will share the unique clinical features of two such patients , from my early days as a neurologist . The first was a sexagenarian whose job involved greeting guests in a lodging facility and taking them to their rooms from the registration desk . He started experiencing increasing difficulty for getting onto the elevator soon after the door opens ; he simply stood “ frozen ” and often the elevator would leave without him . He was not too concerned with the problem , despite warnings from the manager . However , soon a frightening incidence forced him to seek medical help . He lived within walking distance to his workplace ; there was a railway crossing on the way to his home and it was not uncommon for pedestrians to simply walk across the tracks . It so happened that he was trying to cross the tracks one day and saw the train approaching . Instead of jumping away , he froze and stood on the tracks facing the oncoming train . He would have been run over by the train , had it not been for a good Samaritan pulling him away from the track in the nick of time . This shocking incident finally prompted him to seek medical help . The family MD could not figure out the problem and referred him to the neurologist . The patient exhibited several features of Parkinson ’ s disease , which is well-known to cause FOG . There was initial improvement with levodopa therapy , but after two years , the freezing episodes started occurring again .
The second patient turned out to be much more diagnostically challenging . He was a 15-year-old who was nicknamed the “ littering boy ” in school as he had the strange habit of throwing paper balls in front of him while walking . His explanation was that he could not walk forwards without stepping over an object like the paper ball . The school principal was at her wits end as frequent admonitions were of no use . The parents were equally frustrated and fed up . The patient was also clumsy and apparently had the worst handwriting in the class . Prompted by his pediatrician , the youngster was brought for neuro evaluation . I noted that the boy was dysarthric and had cerebellar ataxia in addition to the significant difficulty for walking due to a combination of freezing and start hesitation . In addition , he had a brownish ring in the periphery of his cornea close to the limbus ( possible Kayser-Fleischer ring ), which raised the possibility of Wilson ’ s disease . The serum ceruloplasmin level was low , which confirmed the diagnosis . 2 Genetic studies were not available at that time to identify mutations in the copper binding domain of the ATP7B gene .
The freezing of gait , a disabling motor symptom in Parkinson ’ s disease , can affect quality of life and cause falls resulting in injuries . Turning or attempting to walk through doorways appear to trigger freezing of gait in many patients . A similar phenomenon , inability to initiate walking from a static position , gait ignition failure ( GIF ) may also cause problems in patients with Parkinson ’ s disease . FOG and GIF can be difficult to treat ; adjusting dopaminergic therapies to reduce “ off time ” is often the first step . It is anticipated that technological advances in deep brain stimulation are likely to provide relief from FOG in the future . The effect of stimulation of additional areas of the brain such as the pedunculopontine nucleus ( PPN ) and the spinal cord are also being evaluated . Several cognitive and behavioral techniques are used including robot assisted gait training . 3 , 4 Even with this vast array of treatment options , it is somewhat frustrating that a uniformly effective treatment for FOG is still lacking .
Let me conclude with an optimistic quote from the inspirational author , Orison Swett Marden : “ There is no medicine like hope , no incentive so great , and no tonic so powerful as expectation of something tomorrow .”
References
1
Santamaria-Garcia H et al . A lesion model of envy and schadenfreude : legal , deservingness and moral dimensions as revealed by neurodegeneration . Brain 2017 ; 140 : 3357-3377 .
2
Iyer V et al . Start hesitation overcome by obstacle placement in Wilson ’ s disease . Neurology ( India ) 1981 ; 29 : 84-87 .
3
Cui CK , Lewis SJG . Future therapeutic strategies for freezing of gait in Parkinson ’ s disease . Front Hum Neurosci 2021 ; 15 : 741918 .
4
Lo AC et al . Reduction of freezing of gait in Parkinson ’ s disease by repetitive robot-assisted treadmill training : A pilot study . Jf NeuroEngineering Rehabil
2010 ; 7 : 51 .
Dr . Iyer practices at the Neurodiagnostic Center of Louisville and is a retired professor of neurology at the University of Louisville School of Medicine .
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