One of the most humbling, meaningful aspects of mentoring neurologic physical therapy residents for me is that it snaps one out of the ivory tower of academia and into the realities of clinical practice. My experiences this week illustrated, more than ever, that physical therapists are instrumental in the process of neurologic differential diagnosis. Physical therapists identify signs related to changes in neurologic status that may be emergent. Due to this knowledge, they have a responsibility to ensure that the patient is referred to the appropriate practitioner for care. On a daily basis, physical therapists conduct evaluations to determine the most appropriate interventions based upon a pathophysiologic diagnosis. I will provide two examples from my dose of reality this week.
One of the patients I saw this week with our neurologic physical therapy resident, who just graduated from a doctor of physical therapy program in May and started her residency one month ago, was a patient sent to outpatient physical therapy with the diagnosis of "occipital neuralgia." No further history was provided by the referral source, a neurologist, but the patient reported a history of an internal carotid aneurysm that she was told was inoperable. Further investigation of the medical record by the physical therapist revealed an expanding aneurysm in the junction of the internal carotid/posterior communicating artery. She was complaining of headaches that had two characteristics. One set of symptoms related to suboccipital pain; the other related to right-sided headache and pressure behind the right eye that was constant.
Throughout her evaluation, the resident noted that the patient seemed to have difficulty following directions and complained of dizziness when she attempted standard cranial nerve assessments associated with her differential diagnosis to determine the cause of the occipital neuralgia. It was about this time that I entered the clinic, and the resident asked me to see this patient with her since she was uncertain about the inconsistencies in her findings. Upon questioning the patient and observing her inability to follow simple directions (eg, follow my finger on a gaze assessment), I decided to complete the Mini-Mental State Exam (MMSE).1 The patient scored 15 out of 30, an indication of severe dementia. She demonstrated evidence of anomia, ideational apraxia, severe short-term memory loss (she could not register and repeat three items), and inability to construct a sentence. In addition to her complaints of right-sided headache, we confirmed that she had slowly reacting pupillary constriction and no corneal blink reflex on the right.
Are these findings consistent with "occipital neuralgia"? Would you continue to see this patient in your physical therapy practice without further follow-up by a physician? This is an example of neurologic differential diagnosis by a physical therapist. As a physical therapist, I cannot prescribe the appropriate tests to rule in or rule out increased intracranial pressure (ICP). Nor can I determine what may be the cause of the increase in ICP. But I surely can identify the signs and symptoms of increased ICP and changes in cognitive status that are not consistent with previous functional levels, and ensure that this patient gets the follow-up she requires. In Sullivan et al,2 my collaborators and I discuss the differential diagnosis process that physical therapists use in the real setting of clinical practice. This case illustrates many of the points we emphasized in that publication: that physical therapists must go through a clinical decision-making process that clears the patient for safe and effective physical therapy treatment.
Additionally, it is common for physical therapists to make the correct pathophysiologic diagnosis and often it is imperative that they do in order to select and apply the appropriate intervention. The other example this week was a 52-year-old woman who was referred to the clinic for treatment of dizziness due to Meniere's disease. Meniere's disease is a relatively rare diagnosis characterized by recurrent attacks of vertigo and deafness. During the patient history, she reported that she has total right-side vocal cord paralysis, with onset approximately eight months prior, that has been attributed to radiation for thyroid cancer in 1994. Physical examination revealed that she had one acute episode of vertigo approximately six months prior that had gradually lessened over time, but she still had complaints of dizziness when going to lie on her right side or when coming up to sitting from a forward lean position. Cranial nerve examination revealed no gag reflex and hypersensitivity to pinprick in V1 and V2 of the trigeminal distribution on the right. Tinnitus and feeling of fullness in the right ear were also revealed, but hearing was normal (confirmed by audiologist examination). Further background investigation on thyroid cancer revealed that former cancer patients who receive radiation may experience bilateral paralysis of the vocal cords up to 20 years later, but it is not common to have unilateral paralysis.
Most likely, this patient did not have Meniere's disease, and may have a positional vestibular disorder such as benign paroxysmal positional vertigo (BPPV); however, neither of these conditions would present with the cranial nerve findings present. Often physical therapists are referred patients with the diagnosis of "dizziness." This is not a diagnosis but a symptom of vestibular disease that may be of peripheral or central origin. Physical therapists often determine the differential diagnosis between central and peripheral vestibular disorders. If the therapist suspects BPPV, performs the Dix-Hallpike maneuver, and the patient responds, the therapist has differentially diagnosed the pathophysiologic problem correctly and performed the intervention appropriate to resolve that pathophysiology. For our case, the repositioning maneuver provided some relief but did not account for the whole presentation of this patient. Once again, the therapist has participated in the differential diagnosis process in that Meniere's disease is ruled out. Vertigo with positional changes, significant cranial nerve signs, and progressive complaints of headache and dizziness would suggest that a cranial MRI is indicated to rule out acoustic neuroma, or an even worse possibility, a basal skull meningioma. Immediate consultation with the referring physician to share these additional neurologic findings is appropriate.
In the June 2007 issue of Physical Therapy, Coffin-Zadai3 proposed that physical therapists should unite to develop a movement system diagnostic and classification system. This article was followed by a case-study series by Scheets et al4 regarding the use of movement system diagnoses whereby movement system impairment diagnoses can be matched to intervention. Unfortunately, despite an effort on my part to use the Movement System Diagnoses for Neuromuscular Conditions provided in the online Supplemental Appendix 1,5 I could not find an adequate way to use this system to address the clinical situation that we faced. For example, for the second patient I presented who had an impairment associated with dizziness, my diagnostic choices are Movement Pattern Coordination Deficit, Perceptual Deficit, or Sensory Detection Deficit. This does not help guide my choice of intervention. However, determining if the patient's complaints of dizziness are consistent with Meniere's disease or BPPV would allow me to select the most appropriate intervention given the pathophysiology. In the former, I would prescribe a program that gradates activity to acute vertiginous episodes. In the latter, I would prescribe repositioning techniques and exercises for vestibular accommodation.
We need to open the discussion regarding the diagnostic process that physical therapists engage in on a daily basis. Our training is rich in physiology, pathophysiology, and anatomy along with depth in the influence of the cardiopulmonary, neuromuscular, and musculoskeletal systems on movement dysfunction. Physical therapists are translational practitioners that bring our science-based understanding of both pathophysiology and pathokinesiology with the functional consequences caused by movement dysfunction. Physical therapists evaluate and treat movement dysfunction at the level of pathophysiology (eg, BPPV) and at the level of skill acquisition. To increase skill for the person with movement dysfunction, the physical therapist develops a program that is not only focused at the impairment level but includes practice of movements and tasks that will return the person to the functional and participation levels that will improve their quality of life. A diagnostic system that is limited to movement related impairments will not adequately address the scope of physical therapist practice since it does not address our role in the diagnosis of pathophysiology and ignores the complexity of factors and needs that affect the individual with a health condition as reflected in the International Classification of Function.6
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