FUNCTIONAL SYMPTOMS IN NEUROLOGY: MANAGEMENT– October 29 2015
J Stone, A Carson, M Sharpe
In this article we offer an approach to management of functional symptoms based on our own experience and on the evidence from other specialities (because the evidence from neurology is so slim). We also tackle some of the most difficult questions in this area. What causes functional symptoms? Does treatment really work? What about malingering?
We give two example cases adapted from real patients to illustrate our approach.
WHAT CAUSES FUNCTIONAL SYMPTOMS?
EXPLAINING THE DIAGNOSIS
Early management of functional symptoms involves demonstrating to the patient that you believe them and that you recognise their symptoms as being common and potentially reversible. A lot more research is needed in to the optimum approach but our experience is that using the ‘‘functional model’’ of symptom generation allows a transparent explanation and interaction with the patient that can facilitate later physical and psychological treatments. Much of the core of a cognitive behavioural approach to treatment is in fact simple advice about exercise, sleep, and ways about thinking about symptoms that can be given effectively by a neurologist. While it is unreasonable to expect everyone to get better, it is also a mistake to think that a neurologist cannot make a difference, even in a limited time.
“Objective Conversion disorder is the presence of neurological symptoms that are not due to neurological disease and are thought to be psychological in origin. It is assumed that patients have normal brain anatomy; structural brain abnormalities of potential aetiological relevance generally preclude the diagnosis. However, it remains possible there are subtle neuroanatomical differences that are only discernable at the group, rather than at the patient level. We aimed to test this hypothesis by comparing high-resolution MRI scans of patients with motor conversion disorder with healthy controls using a Region Of Interest (ROI) approach.”
“15 patients with ICD-10 diagnoses of motor conversion disorder with symptom onset within 2 years and 31 age- and sex-matched healthy controls had high resolution Spoiled Gradient Recalled sequence scanning on a 3 T MRI scanner. ROIs, chosen on the basis of previous reports or on theoretical grounds, were placed on the bilateral amygdala, thalamus, caudate and lentiform nuclei. Freesurfer V.5.0 software was used to identify, label and measure the anatomical structure volumes.”
“There were uncorrected reductions in bilateral thalamic volume in patients compared to controls (left thalamus p=0.001, right thalamus p=0.002). Intracranial volume was also reduced in patients, however (p=0.012), and when corrected for this the thalamic reductions remained significant (left thalamus p=0.02, right thalamus p=0.05) and there was a significant (p=0.05) reduction in the volume of the left, but not the right, lentiform nucleus. There were no other ROI differences.”
“We have found evidence for reduced volume of the thalamus in conversion disorder. These changes could be secondary to chronic limb immobility as there is some evidence of similar thalamic volume losses after limb amputation. Longitudinal studies of conversion disorder patients, particularly re-scanning post recovery, would be needed to address this question. If thalamic volume changes are found to correlate to level of limb disuse such changes would be a strong indicator of the severity of this disorder in terms of the amount of actual, as well as reported, immobility. However, a functional imaging study (Vuilleumier et al, 2001) has found evidence of reduced activation of the thalamus (and basal ganglia) in symptomatic conversion disorder patients and it therefore remains possible these changes could be of aetiological or mechanistic significance.”
Functional Weakness: Clues To Mechanism From The Nature Of Onset – August 11 2011
“Functional weakness describes weakness which is inconsistent and incongruent with disease. It is also referred to as motor conversion disorder (DSM-IV), dissociative motor disorder (ICD-10) and ‘psychogenic’ paralysis. Studies of aetiology have focused on risk factors such as childhood adversity and life events; information on the nature and circumstance of symptom onset may shed light on the mechanism of symptom formation. Aim To describe the mode of onset, associated symptoms and circumstances at the onset of functional weakness.”
“Retrospective interviews administered to 107 adults with functional weakness of <2 years’ duration.”
“The sample was 79% female, mean age 39 years and median duration of weakness 9 months. Three distinct modes of onset were discerned. These were: sudden (n¼49, 46%), present on waking (or from general anaesthesia) (n¼16, 13%) or gradual (n¼42, 39%). In ‘sudden onset’ cases, panic (n¼29, 59%), dissociative symptoms (n¼19, 39%) and injury to the relevant limb (n¼10, 20%) were commonly associated with onset. Other associated symptoms were non-epileptic attacks, migraine, fatigue and sleep paralysis. In six patients the weakness was noticed ﬁrst by a health professional. In 16% of all patients, no potentially relevant factors could be discerned.”
“The onset of functional weakness is commonly sudden. Examining symptoms and circumstances associated closely with the onset suggests hypotheses for the mechanism of onset of weakness in vulnerable individuals.”
Psychogenic Movement Disorders And Motor Conversion: A Roadmap For Collaboration Between Neurology And Psychiatry – March 2011
“Psychogenic movement disorders are characterized by the presence of abnormal movements or absence of normal movement not attributable to an organic neurologic disorder and considered to be psychologically mediated. A large movement disorder clinic estimated the prevalence of psychogenic movement disorders to be 5.3%, a rate higher than both the prevalence of Huntington disease and restless leg syndrome in the same clinic. While recent imaging research has pointed to an abnormal network of neuronal activation, the mainstay of treatment for these patients remains psychotherapy.”
“Psychogenic movement disorders have been called a “crisis for neurology” as patients are often unaccepting of the diagnosis, few treatments exist, and few patients have been shown to improve in the published case series. Worsening this already grim picture is lack of discourse between neurology and psychiatry regarding these patients; while this is an ideal disease model for partnership between psychiatry and neurology, there are significant differences between the two fields’ perspectives towards this disorder that make collaboration difficult. Differences in terminology alone begin to illustrate this divide: the term “psychogenic movement disorder” has gained popularity among many neurologists and is presented as a separate chapter in movement disorder textbooks, but this phrase has little diagnostic specificity for psychiatrists and is not found in the current Diagnostic and Statistical Manual of Psychiatry (DSM-IV-TR) or textbooks of psychiatry. The differences between neurology and psychiatry go beyond terminology and extend into nosology, as not all patients with psychogenic movement disorders meet criteria for its closest approximation in the DSM-IV-TR, conversion disorder with motor symptom or deficit.”
“Information on the nature and relative frequency of diagnoses made in referrals to neurology outpatient clinics is an important guide to priorities in services, teaching and research. Previous studies of this topic have been limited by being of only single centres or lacking in detail. We aimed to describe the neurological diagnoses made in a large series of referrals to neurology outpatient clinics.”
“Newly referred outpatients attending neurology clinics in all the NHS neurological centres in Scotland, UK were recruited over a period of 15 months. The assessing neurologists recorded the initial diagnosis they made. An additional rating of the degree to which the neurologist considered the patient’s symptoms to be explained by disease was used to categorise those diagnoses that simply described a symptom such as ‘fatigue’.”
“Three thousand seven hundred and eighty-one patients participated (91% of those eligible). The commonest categories of diagnosis made were: headache (19%), functional and psychological symptoms (16%), epilepsy (14%), peripheral nerve disorders (11%), miscellaneous neurological disorders (10%), demyelination (7%), spinal disorders (6%), Parkinson’s Disease/movement disorders (6%), and syncope (4%). Detailed breakdowns of each category are provided.”
“Headache, functional/psychological disorders and epilepsy are the most common diagnoses in new patient referral to neurological services. This information should be used to shape priorities for services, teaching and research.”
Neurologists’ Understanding And Manangement Of Conversion Disorder – February 16 2011
“Neurologists’ understanding and management of conversion disorder. This is a research study looking at neurologists in the UK. Study was questioner based, and it examines how neurologist understand conversion disorder, and what they tell their patients. The one thing that is not completely clear is if most neurologists included in the study saw FND separate as Conversion Disorder or see them as the same. A common source of ambiguity as doctors are finding almost half of Conversion patients do not show signs of psychological manifestations nor have a history of psychological illness.”