Recurrent fall in Parkinson Disease: Possible Role of the Proprioceptive and Vestibular Systems

Research Article

Austin J Clin Neurol 2016; 3(1): 1087.

Recurrent fall in Parkinson Disease: Possible Role of the Proprioceptive and Vestibular Systems

Lieberman A1*, Deep A1 and Lockhart T2

¹Muhammad Ali Parkinson Center, St. Joseph’s Hospital and Medical Center, USA

²Department of Bio-Engineering, Arizona State University, USA

*Corresponding author: SAbraham Lieberman, Lonnie and Muhammad Ali Research Chair in Parkinson Disease, Director Bob & Renee Parsons’ Fall Reduction Center, USA

Received: May 29, 2016; Accepted: July 08, 2016; Published: July 11, 2016


Falls are a major risk for Parkinson disease patients (PD). We sought to understand why some patients fall once and some more than once (recurrent fallers). Recurrent fallers had PD significantly longer, 12.6 + 7.0 versus 5.9 + 4.5 years, had significantly higher motor MDS UPDRS scores” 31.2 + 12.7 versus 19.7 + 8.3, and walked with significantly shorter steps: 0.37 + 0.18 meters versus 0.52 + 0.19 meters than single fallers.

The major difference between single fallers and recurrent fallers was an inability of recurrent fallers to stand on one leg for < 3 seconds: 95% versus 11 %, odds ratio 178 CI 95% 39.5-801.2 We attribute this inability to stand on one leg for < 3 seconds to an impairment of proprioceptive function and or possibly vestibular (utricle and sacculus) function. When a person stands on one leg, they effectively decrease their proprioceptive input by 50%.

In two studies of tremor in PD we implicated proprioceptive and vestibular impairments. Such impairments were demonstrated more than 50 years ago by J Purdon Martin, the eminent English neurologist, in post-encephalitic Parkinson patients. Based on our studies of recurrent falls in PD we believe proprioceptive and vestibular impairments may be major risk factors in falls.

Keywords: Parkinson disease; Falls; Proprioception


Falls, especially recurrent falls, are a major cause of disability in Parkinson disease (PD) [1,2]. In a study of 761 hospital admissions for PD only 15% were for the management of PD, while 39% were for falls [1]. A major risk for recurrent falls is a previous history of a fall. PD patients who fall once may do so because of PD or because of factors such as poor eyesight, leg weakness, and environmental hazards. They do not differ, substantially from PD patients who don’t fall in regard to age, duration or severity of PD [3-5]. Some PD patients fall repeatedly [3]. They do differ from patients with PD who do not fall in regard to age, duration and severity of PD [5].

There is variability in the reported prevalence of falls in PD: from 11% to 68% [3-14]. The variability depends on whether specific fall risk factors are excluded. These include visual loss, neuropathy resulting in leg weakness or proprioceptive loss, orthostatic hypotension resulting from anti-hypertensives or imbalance resulting from tranquillizers, sedatives or alcohol. The variability also includes whether persons with evolving atypical Parkinson disorders such as Progressive Supranuclear Palsy (PSP) or Multiple System Atrophy (MSA) are excluded. Although patients with these disorders represent only a small number of patients a high percentage of them fall [6].


We only analyzed serious falls where all 4 limbs, the skull or buttocks hit the ground, with patients sustaining a fracture or soft tissue injury. Patients who had a serious fall sought attention, within 24-48 hours, in an Emergency Room, an Urgent Care Center, their local physician, or us.

All patients were examined using the Movement Disorder Society (MDS) motor portion and its sub-tests part of the Unified Parkinson Disease Rating System [15] and selected subtests: freezing of gait (FOG) subtest, postural instability (PI), utilizing the “pull test”. All patients were studied using the BNI balance scale [16]. This included the ability of a patient to stand on one leg for at least 3 seconds: the One-Legged Stance, a test of postural instability (PI). All patients walked 7.63 meters (25 feet). The number of steps taken was counted, divided by 7.63 meters, and an average was obtained.

We excluded patients with dementia, Mini-Mental Status Examinations, MMSE, < 24. Although dementia can be a risk for falling, many PD patients with dementia are without a care-giver for at least 4 hours. Thus we were uncertain if they reported their falls. We excluded patients who were legally blind. We excluded patients with orthostatic hypotension. Although orthostatic hypotension can be part of PD, it can also result from the use of anti-hypertensives, diuretics or dehydration [17]. We excluded patients with neuropathy when it resulted in impaired proprioception or weakness and we excluded patients with major orthopedic problems [13,14].

In our study of single versus recurrent fallers [3], we examined 452 patients. We excluded 51 patients for the reasons enumerated above. We next excluded patients who did not fall. We then compared 161 single fallers with 44 recurrent fallers, a total of 205 patients.

In a second and separate study, we distinguished the tremor of PD from the tremor of Essential Tremor [18]. Although the tremor of PD usually, but not always, differs from essential tremor (ET), there is no simple bedside test to distinguish PD from ET. We studied 50 consecutive tremor-dominant PD patients (mean age: 63.4 years; mean disease duration: 4.9 years) and 35 consecutive ET patients (mean age: 64.1 years; mean disease duration: 12.5 years). Among PD patients, 31 had a bilateral tremor and among ET patients, 29 patients had a bilateral tremor. Patients sat opposite the examiner and pointed both index fingers at the examiner’s index fingers. Then they closed their eyes. Within 15 seconds, one or rarely both of the patient’s index fingers moved, were displaced, either upward or laterally.

In a third and separate study, we examined the above phenomenon in 104 PD patients: 72 without a tremor and 32 with a minimal tremor to see if the displacement is related to the disease or the tremor [19]. Sixty-eight of the 72 patients without tremor, 94%, exhibited finger displacement suggesting the phenomenon is related to PD. None of the 104 patients were demented.

All patients were informed that the information collected could be used for research but that they personally could not be identified. Approval for the analysis was obtained by the St. Joseph’s Hospital institutional review board. No patients were compensated. As the evaluations were part of the patient’s routine care no special consent other than the standard signed consent obtained from all patients at the time their visit was obtained.

Continuous variables were analyzed using t-tests and categorical variables were analyzed using chi-square tests.


In our study of single versus recurrent fallers [3] 87.5 % of single fallers were on levodopa, among recurrent fallers 100 % were on levodopa [3]. 40% of single fallers had dyskinesias, 56% of recurrent fallers had dyskinesias. Although a higher percent of recurrent fallers had dyskinesias we cannot comment on the contribution of dyskinesias to falls. This is because we recorded only the presence, not the severity of dyskinesias.

We studied 205 patients: 113 men, 92 women of whom 161 (79%) fell once and 44 (21%) fell more than once. See Tables 1, 2.

Citation: Lieberman A, Deep A and Lockhart T. Recurrent fall in Parkinson Disease: Possible Role of the Proprioceptive and Vestibular Systems. Austin J Clin Neurol 2016; 3(1): 1087.