Diagnostic criteria Diagnostic criteria have been developed to operationalize diag- nosis o f PMDs. Th e most widely used criteria, developed by Fahn and Williams (36), divide PMDs in to four categories of diagnostic certainty: documented, clinically established, prob- able, and possible. In fact, these criteria were fi rst developed for psychogenic dystonia alone , but were later expanded to cover all PMDs. Gupta and Lang (37) have suggested revisions t o these criteria (Table 31.2) which delete the \200\230possible \200\231 category as being not suffi ciently specifi c for PMDs, and also seek to introduce the A \200\230paroxysmal \200\231 component to the disorder is an important clue that the diso rder may be psychogenic, but \200\230pure \200\231 psychogenic Table 31.2 Diagnostic classi \201 cation of psychogenic movement disorders Fahn and Willia ms (36) Persistent relief by psychotherapy, suggestion, or placebo has been demonstrated, w hich may be helped by physiotherapy, or the patient was seen without the movement disorder when believing him/herself unobserved Gupta and Lang (37) Persistent relief by psychotherapy, suggestion, or placebo has been dem onstrated, which may be helped by physiotherapy, or the patient was seen without the moveme nt disorder when believing him/herself unobserved 1 Documented Clinically established Th e movement disorder is incongruent/inconsistent with typical movement disorder plus at l east one of the following three: \227\206 other psychogenic signs \227\206 multiple somat izations \227\206 obvious psychiatric disturbance Plus other features: the movement disorder is incongruent/inconsistent with typical movemen t disorder plus at least one of the following three * : \227\206 other psychogenic signs \227\206 multiple somatizations \227\206 obvious psychiatric disturbance Minus other featu res: the movement disorder is incongruent/ inconsistent with typical movement disorder with out any other features * \227\206 Th e movement disorder is incongruent/inconsistent Probable ** with typical movement disorder \227\206 Th e movement disorder is congruent/consistent and there are psychogenic signs \227\206 Th e movement disorder is congruent/consistent and there are multiple somatizations Possible *** \227\206 Th e movement disorder is congruent/consistent and \227\206 Th e movement disorder is congruent/consistent and there are there is evidence of an emotional disturbance psychogenic signs \227\206 Th e movement disorder is congruent/consistent and there are multiple somatizations \227\206 Th e movement disorder is congruent/consistent and there is evidence of an emotional disturbance \227\206 Electrophysiological evidence proving a psychogenic movement Laboratory-supported de \201 nite disorder (primarily in cases of psychogenic tremor and psychogenic myoclonus) According to the Gupta and Lang proposal, the \200\230documented \200\231 and \200\230cli nically established \200\231 \200\230plus or minus other features \200\231 categories can be grouped under the term \200\230clinically de \201 nite \200\231. Gupta and Lang propose reclassifying patients in the \200\230probable \200\231 category according to the Fahn and Williams classi \201 cation, under \200\230clinically establish ed \200\231 (those with incongruent/ inconsistent movement disorders) or \200\230possible \200\231 (those with congruent/consistent movement disorders). * Gupta and Lang also questioned the utility of retaining the \200\230possible \200\231 c ategory as this generally represents patients with organic movement disorders with addition al psychiatric problems rather than a true \200\230possible psychogenic movement disorder \200\231. CHAPTER 31 Psychogenic Movement Disorders 343 concept of a laboratory-supported level of certainty, for exam- ple using recordings of pre -movement potentials in psychogenic myoclonus. Shill and Gerber (38) proposed alternative c riteria, but these have been criticized for relying so heavily on historical factors such a s \200\230disease modeling \200\231 that it is possible to make a diagnosis of PMD without reference to the movement disorder phenomenology. disorder arose from a malfunction in the part of the brain receiving and interpreting senso ry and aff ective information. More modern conceptions of somatoform disorders have tended to focus on the way in which normal physiological sensory input might be mis- interpreted b y an individual as pathological and signifying illness (41). Models, such as that proposed by Kirmayer and Taillefer (41), propose an interaction between somatic sensations (normal p hysio- logical experiences, those induced by emotional arousal, sensations arising from org anic physical illness), pre-existing personality, previous illness experience, and societal factors that enhance the secondary gain of the sick role (disability benefi ts, social res ponse of others to illness) (41). Th e fundamental neurobiological pro cess that underpins this model is excessive attention that is directed towards the triggering somatic sensation s which amplifi es them and maintains the patient \200\231s abnormal (enhanced) perception of these sensations. Th ese are then reported by the patient as symp- toms (e.g. pain). Recently, these criteria have been assessed with regard to inter-rater reliability, and hav e been found to demonstrate moder- ate to poor reliability for the probable and possible ca tegories. Th is work suggests that new criteria, which perhaps include more spe- cifi c dir ection as to the positive physical signs that predict PMDs rather than the unspecifi ed \200\230incongruency \200\231 with organic movement disorders, might improve reliability. Pathophysiology We have already discussed how the movements that occur as part of PMDs are quantifi ably diff erent from those seen in organic movement disorders mainly by virtue of the fact that they resemble movements that are made voluntarily. Th is leads naturally to t wo logical possibilities. Either movements are deliberately feigned by patients, or there m ust be another process by which movements that appear voluntary are not experienced as such by patients. Th e category of conversion disorder is based on the concept introduced by Breuer and Freud between 1893 and 1895, and later extended by Freud alone. Here, the role of a psychologica l stres- sor is paramount. Th is stressor is proposed to set off a defensive reaction of su ppressing (or repressing) the memory of this stres- sor. While this may relieve the distres s associated with the stressor, Breuer and Freud proposed that the \200\230psychic energy \200\231 displaced from its proper place by this process is \200\230converted \200\231 int o a somatic symp- tom which may bear some symbolic association with the original stressor ( 42). Th is somatic symptom is unconscious as the source of the energetic displacement is re pressed and the process occurs outside awareness. Although the energy displacement mechanis m proposed by Freud has been discarded, the idea that functional symptoms relate to a conve rsion of psychological distress retains considerable popularity. It is generally acknowledged to be very diffi cult to distinguish malingering from \200 \230true \200\231 psychogenic movement disorder, but the consensus of opinion is that malin gering is likely to be rare and is not a satisfying explanation for the disorder in the maj ority of patients with PMDs (and indeed other functional disorders). Th is opinion is given some limited but important support from func- tional imaging studies in functional paralys is, where patterns of brain activation in patients attempting to move their apparently para lyzed leg are diff erent from those in subjects feigning paralysis (39, 40). Th is does not amount to proof that these patients are not malingering, but it is at least supportive evi dence. Th e category of dissociative disorder is based on another nine- teenth century formulation to explain functional symptoms pro- posed by Janet (43). Here, in individuals with a patho logically weak mental state, psychological stressors were proposed to lead to a narrowing o f attentional focus and a resulting disregard of certain sensory input. Th is provided an e xplanation for hysterical sensory loss, a symptom which both Janet and Charcot proposed as being an essential clinical feature of hysteria. Th e attentional dysfunction proposed by t his theory has continued to infl uence more mod- ern models of functional symptoms. Th ese modern theories have rejected the concept that dissociation only occurs in those with pre-e xisting \200\230mental weakness \200\231, but have instead conceptualized it as a normal p henomenon that becomes disrupted in those with functional symptoms. Th us dissociation is a normal and advanta- geous mode of cognitive processing that allows intentional activity to continue in an automatic non-attended fashion while attentional resources are directed els ewhere. However, in pathological states (hypnosis, functional symptoms), certain patterns o f automatic activity (e.g. inhibition of limb movement) can be triggered uncon- sciously, a nd therefore are experienced by the person as outside their control. Th e current categorization of functional symptoms found in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV TR) refl ects infl uential psychologically based models to explain patho- physiology of functional symptoms. It recognizes three diagnostic groups: somatoform disorders, conversion disorder, and dissocia- tive disorder. Somatoform disorde rs are those where somatic com- plaints such as pain and fatigue are present with no clear physical cause, and encompass somatization disorder (Briquet \200\231s syndrome), where the re is a history of multiple physical complaints including pain aff ecting at least four dif f erent parts or functions of the body, at least two gastrointestinal symptoms, at least on e sexual or repro- ductive symptom, and at least one symptom that mimics a neu- rological c ondition. Conversion disorder is defi ned as occurring when patients present with one or mo re symptoms aff ecting move- ment or senses that cannot be explained by a physical cause an d is preceded by confl icts or stressors in the patient \200\231s life. Dissociative disord ers are those where there is a specifi c abnormality of mem- ory, perception, or identity w hich cannot be explained by a physical cause. Th e logical position taken by all of these theories is that patients are unaware of the wa y symptoms are produced (i.e. they are not feigning) as the locus of symptom production is at a low level within the nervous system. For somatoform disorders, this is the amplifi - c ation of bottom-up sensory input. For conversion disorder, this is the inhibition of primar y motor or sensory areas. In dissociative Th is current tripartite classifi cation system is underpinned by three partially overlappi ng theoretical approaches to functional symptoms. Th e category of somatoform disorders is based heavily on Briquet \200\231s original description of chronically aff ected polysymp- tomatic patients, and perhaps also Briquet \200\231s original theory that the Oxford Textbook of Movement Disorders 344 disorders, this is the \200\230automatic \200\231 activation of pre-established pat- terns of motor or sensory activity. In all these models, functional symptoms have a bottom-up ca use but no top-down purpose, lead- ing to symptoms that are experienced as involuntary and \200\230unwilled \200\231. Th is contrasts directly with symptoms produced by feigning/mal in- gering which involve top-down purposes , but no bottom-up cause , and as a result shoul d be experienced by the individual as deliberate willed acts. expectation about symptoms is driving perception of symptom severity. Th e interaction betw een expectations (or prior predic- tions) about sensory data and the sensory data actually received is central to modern Bayesian theories of brain function (48). Th ese data fi t wi thin that framework, and may provide a novel direction for future pathophysiological work. Unfortunately, this discussion of the pathophysiology of PMDs does not provide a clear answ er to the origins of these perplexing symptoms, but it does highlight the defi ciencies of purely psycho- dynamic explanations for symptoms, and the need for any theory to be impleme nted neurobiologically within known brain structures and mechanisms. Th ere are diffi culties with all these approaches. First, the expected high rates of psych ological trauma in patients with functional symp- toms, including PMD, are not found in con trolled studies (11). One explanation for this is that memory for such traumatic events is repressed, and therefore is not available for conscious report, but the circularity of this argument makes it diffi cult to test experi- mentally. Secondly, the characteristics of th e physical symptoms in patients with functional disorders, including PMD, that diff erenti- ate them from patients with organic disorders suggest a high-level or \200\230top-down \200\231 process. Movement impairments disappear when attention is drawn away from them, an d they oft en fi t with beliefs about illness rather than physiological reality (e.g. patie nts who report tubular visual fi eld defects which break the laws of optics). Most of the t heories discussed above suggest that an \200\230emotional \200\231 area of the brain inhib its or disrupts a low-level motor or sensory brain region, producing a symptom which is not accessible to con- scious control. Why then should such symptoms require attention to mani fest and conform to high-level beliefs? Treatment PMD treatment begins with an eff ective communication of the diag- nosis to the p atient. Th e previous discussion regarding the absence of triggering life events in many pa tients may provide an expla- nation for the incredulity (and sometimes hostility) that pati ents may demonstrate when receiving a diagnostic explanation for their physical symptoms th at is based on psychological factors. A more general explanation which does not ignore psyc hological factors, but acknowledges the physical triggering factors present in many patient s, is oft en more successful. Th e benefi t of simply explaining the diagnosis, at least in the early stages, has been found to lead to long-term resolution of symptoms in patients w ith psychogenic disorders in general (49). As the outcome for patients with PMDs worsens wi th delayed diagnosis and treatment, a therapeutic strat- egy should be planned immediately aft er giving the diagnosis. Functional imaging seems a natural method with which to approach the pathophysiology of the se disorders, and recent stud- ies in patients with PMD provide some interesting data. Voon and colleagues (44) have demonstrated abnormal connectivity between the amygdala and suppl ementary motor area in patients with PMD when shown emotionally arousing images, suggesting a link between emotional processing and an area involved in motor plan- ning/preparation. Th e same group has also shown a relative decline in activation of the right inferior parie tal lobule in patients with psychogenic tremor by comparing activation patterns while they were tremoring and when they were voluntarily producing tremor (45). Th is area is importan t in making comparisons between expected and perceived sensory data, and the authors sugges t that its underactivation during psychogenic tremor would help generate a mismatch between expected and perceived sensory data, leading to a perception of lack of agency for the mov ement. On the same theme, Edwards and colleagues (46) have shown impairment in the normal t iming of the sense of intention when making a voluntary movement in patients with PMDs comp ared with controls. Most treatments used in patients with organic movement dis- orders are not eff ective in pa tients with PMDs, and iatrogenic damage can occur through use of unnecessary medications an d interventions. Unfortunately, there is little controlled trial data to guide treatment in PMDs, but the limited evidence that is available suggests that a multidisciplinary approac h gives the best chance of benefi t. Psychological intervention can be helpful in patients who con- sider psychological factors to be relevant in symptom develop- ment or maintenance. In patients with clear psychologica l stressors but who are reluctant to engage with this strategy, explaining that cognitive t echniques are commonly used in medicine to help to control physical symptoms (e.g. modern m anagement of chronic pain) may encourage them to try this approach. Hinson and col- leagues (50) conducted a single-blinded clinical trial in 10 patients with PMDs in which the patie nts received 12 one-hour sessions per week of psychodynamic psychotherapy. Patients also re ceived anti- depressants or anxiolytics as indicated. Means for the PMDs rating scale, func tion scores, Hamilton depression scores, and Beck anxi- ety scores all improved. A recent l arge controlled study assessed whether adding input from a guided self-help workbook based on cognitive \200\223behavioral therapy (CBT) to the usual care received by patients with p sychogenic disorders improved outcomes (51). Patients receiving CBT-based guided and usual care reported greater improvement in presenting symptoms and physical func- tion than patie nts receiving usual care alone. In a prospective treat- ment trial of PMDs with antidepress ants, 15 patients with PMDs were treated with citalopram or paroxetine (52). Th ose who did not respond aft er 4 weeks of taking an optimal dose were switched to venlafaxine. Signifi cant improvements were found only in patients In a recent study, patients with psychogenic tremor and with organic tremor were given an a ctigraphy device to wear, similar in size to a wristwatch, capable of continuously monitori ng tremor for days, and at the same time they were asked to fi ll out diaries indicating ho w much of the day they perceived they had tremor (47). Both patient groups overestimated th e amount of time they had tremor as measured by actigraphy, but the psychogenic tremor grou p did so to a much greater extent. Indeed, this group had on average only 4% of the day wit h tremor measured by the actigraph, compared with diary ratings indicating that they percei ved tremor to be present for 84% of the day. Th e subjects were all explicitly informed of the purpose of the study, and therefore these results do not support the suggestion that th ese patients are malinger- ing. Instead, it suggests that an important component of belief or CHAPTER 31 Psychogenic Movement Disorders 345 with \200\230primary conversion symptoms \200\231 and recent or current depres- sive or an xiety disorder, and not in those with a diagnosis of soma- tization disorder. symptoms at last follow-up (3 \200\2235 years aft er presentation) (13). Factors that predi cted a favorable outcome were a short dura- tion of illness, the patient \200\231s percepti on of eff ective treatment by the physician, and the presence of a co-morbid psychiatric di agnosis of depression or anxiety (which is therefore amenable to treatment) (58, 59). Negat ive outcome at long-term follow-up is associated with long-standing symptoms (more than 6 m onths) (3), insidious onset of movements, and a primary psychiatric disorder of hypo- chond riasis, factitious disorder, or malingering (52). Rehabilitation with physiotherapy and occupational therapy has face validity as a technique to treat motor symptoms and is likely to be acceptable to more patients than psychotherape utic treatments. Physical rehabilitation may improve outcome in PMD in combi- nation with p sychotherapy (19), but controlled studies are lacking. Preliminary evidence for regular low - to medium-intensity walking exercise, which is known to be eff ective in the treatment of depres- sion or anxiety, has been investigated in a single-blind study of 16 patients with PMDs (53). Aft er a 12-week program, 62% of the enrolled patients showed a marked improvem ent (mean improve- ment of 70% in total score in the Psychogenic Movement Disorder Rating s cale compared with baseline) with no adverse eff ects in any participant. Conclusions PMDs are common and disabling conditions, and as part of the spectrum of functi onal neurological illness represent a major source of distress and a huge fi nancial burden to health and social care systems. Diagnosis is oft en challenging, and an important futur e line of research is to develop improved objective stand- ardized diagnostic criteria. Th ere has been a recent resurgence of research interest in functional disorders in general, a nd it is hoped that this will lead to improved biological understanding of these disorders. Even without this understanding, pragmatic treatment trials are feasible within this patie nt group. Patients with PMDs can recover, and research is urgently needed to fi nd the most effi - cient treatments and service structures to manage their disabling symptoms. Th ere is continued debate concerning the use of suggestion and placebo as a treatment stra tegy for PMDs. Th e traditional objec- tion to its use is that it erodes patient autonomy a nd the doctor \200\223 patient relationship. However, an informal survey of participants at the Second International Conference on Psychogenic Movement Disorders in April 2009 found that over 50% of the experts present had witnessed the benefi cial eff ects of suggestion i n patients with PMDs (54). No long-term controlled studies with placebo have been reported to date. Additional treatments have been suggested to be eff ective in PMD. For example, intrathecal baclofen was reported to be eff ec- tive in fi xed dystonia compared with placebo (55). Ho wever, placebo control was only used for the initial test dose of intra- thecal baclofen, a nd it is not known whether there was systematic unblinding of the participant by systematic eff ects of the baclofen. Low-frequency repetitive transcranial magnetic stimulation (TMS) achieved symptom relief in 11 patients with psychogenic tremor. 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Index ancillary investigations 8 anhidrosis 131 antecollis 64 anterior forebrain pathway (AFP) 25 anterocollis 179, 195, 197 anterolaterocollis 64 anticholinergics cerebellar degeneration (ACD) 281, 284, 290 drug-induced movement disorders 308 history tak ing 7 sensitivity 2-oxoglutaric aciduria 207 3-methylglutaconic acidaemia 207 4-aminopyridine 275 4-hydroxybu tyric aciduria 207 5-fl uorouracil 290 5-hydroxytryptophan 134, 170 12sRNA gene 122 1000 Ge nomes Project 58 cerebellar tremor 170 myoclonus \200\223dystonia (essential tremor) 164, 165, 180, 258 drug-induced movement disorders 209, 304, task-specifi c tremor 170 alcoholic encephalopathy 236 allopurinol 207 -adrenergic agents 249, 251 \200\2232 -interferon 290, 308 -methyl para-tyrosine 309 -motor neurons 11, 12 -synuclein 129, 134, 151, 152, 154, 155 alprazolam 167 alternating leg muscle activat ion (ALMA) 335 Alzheimer, Alois 3 Alzheimer \200\231s disease (AD) 305, 306, 309, 310 dystonia 184 \200\2235, 196, 209 dystonic tremor 170 Holmes tremor 171 multiple system atro phy 133 parkinsonian tremor 169 Parkinson \200\231s disease 79, 86, 93, 99 thalamic tremor 171 anticholinesterases 305 anticonvulsants see antiepileptics antidepressants ABCD1 gene 296 abductor dysphonia 179 abetalipoproteinaemia (ABL) 294 accelerometry 33, 165 , 166, 168 acebutolol 169 aceruloplasminaemia 123, 227, 243 acetazolamide 185, 270, 271, 27 2, 273, 274, 275, 276, 277, 291 acetylcholine 23 acetylcholinesterase 48 acetylcholinesterase inhibitors 92, 159 acquired h epatocerebral degeneration corticobasal degeneration 146 drug-induced movement disorders 209, 303, corticobasal syndrome 145 and dementia with Lewy bodies 152 diff erential diagnosis 152, 15 3 \200\2234, 260 functional imaging 48 genetics 54, 56 parkinsonism 64, 123 Parkinson \200 \231s disease dementia 107 304, 305 dystonia 209 Huntington \200\231s disease 218 Parkinson \200\231s disease 93, 104, 106 progressive supranuclear palsy 146 psychogenic movement disorders 172, 344 restless le gs syndrome and periodic limb (AHD) 320 \200\2231 acquired immune defi ciency syndrome see AIDS action dystonia 177 action myoclonus renal fa ilure syndrome (AMRFS) 260 amantadine action selection 24 acupuncture 146 acute disseminated encephalomyelitis cerebellar ataxias 286 cerebellar tremor 170 drug-induced movement disorders 305, 306, movements 332 sleep bruxism 335 see also selective serotonin-reuptake (ADEM) 289 310 acute dystonic reactions 182, 209 acute rheumatic fever (ARF) 231, 234 adalimumab 318 Adams , R.D. 257 addiction 25 adductor dysphonia 179 adductor laryngeal dystonia 197 adherence to therapy 8 adrenocorticotrophic hormone (ACTH) 316 adrenoleucodystrophy (ALD) 296 advanced directives 219 aff ective disorders see mood disorders AIDS 321, 322 inhibitors; tricyclic antidepressants Huntington \200\231s disease 218 multiple system atrophy 133 parkinsonian tremor 169 Parkin son \200\231s disease 47, 79, 80, 87, 88, 90, 93 non-motor symptoms 99, 10, 105, 106 antiemetics 209 antiepileptics cerebellar ataxias 289 chorea 236 cortical myoclonus 260 drug-induced movement disorders 20 9, 310 dystonia 209 episodic ataxia 291 Huntington \200\231s disease 218 myoclonus 260, 261 paroxysmal movement disorders 269, 270, Parkinson \200\231s disease dementia 108 progressive supranuclear palsy and corticobasal de generation 145 American Association for the Study of Liver Diseases (AASLD) 244 amine depleters 182 amino aciduria 207 \200\2238 4-aminopyridine 275 amiodarone 7, 290, 305 , 308 amisulpiride 218 amitriptyline 146, 159, 245, 308 ammonium tetrathiomolybdate 244 amp hetamines 236, 251, 307 amphotericin B 305, 308 amyloid plaques 152, 153 \200\2234 amyotrop hic lateral sclerosis 158 \200\2239 anesthetic agents 182, 209 271, 272, 273 chorea 236, 237, 238 drug-induced movement disorders 303, 304 stereotypies 249 tics 251 AIDS dementia complex (ADC) 321 akathisia 304 \200\2235, 309, 310 akinesia, defi nition 5 a kinetic \200\223rigid disorders 5 albendazole 323 albuterol 308 alcohol (ethanol) 321 anti-glutamic acid decarboxylase (anti-GAD) antibodies, ataxia associated with 291 antihistamines 304, 307, 332 antimalarials 209 anti-N-methyl-D-aspartate (anti-NMDA) recept or encephalitis 248 antiphospholipid syndrome 290, 319 cerebellar ataxia 284, 289 Index 348 tics 250 \200\2231 ATXN1 gene 295 ATXN2 gene 295 ATXN3 gene 296 ATXN7 gene 296 atypical par kinsonian disorders see benign hereditary chorea 228 benign paroxysmal vertigo of childhood 275 benserazide 85 benz odiazepines antipsychotics see neuroleptics antispasmodics 154 anxiety myoclonus \200\223dystonia 180 Parkinson \200\231s disease 75, 99, 100, 104 Parkinson \200 \231s disease dementia 107 paroxysmal movement disorders 269 rhythmical movement disorder o f sleep 334 tics 251 Wilson disease 243 alcohol withdrawal 321 corticobasal degeneration 146 drug-induced movement disorders 304, 3 05, corticobasal degeneration/syndrome; multiple system atrophy; progressive supranuclear palsy auditory startle refl ex 6, 37 autism 248, 249 autoimmune diseases 318 \200\22319 310, 311 dystonia 182, 185 Huntington \200\231s disease 218 myoclonus \200\223dystonia 202 paraneoplastic opsoclonus \200\223myoclonus anxiolytics 344 apathy 104, 106, 107, 243 aphasia choreas 231 \200\2235, 237 \200\2238 syndrome 317 autonomic dysfunction paroxysmal movement disorders 270, 271 progressive supranuclear palsy 146 renal disease 320 rhythmical movement disorder of primary progressive 159 progressive non-fl uent 144, 158 dementia with Lewy bodies 152, 154 multiple system atrophy 130 \200\2231, 132 \200\2233 par kinsonism 64 \200\2235 Parkinson \200\231s disease 75 \200\2236, 102 \200\2233 progressive supranuclear palsy 142, 143 autosomal dominant cerebellar ataxias see APOE gene 107 apomorphine 65, 86, 87, 89, 90, 133, 332 APP gene 56 Applied Biosystem 56 apr axia sleep 334 sleep bruxism 335 sleep starts 332 stereotypies 249 stiff person syndrome 316 spinocerebellar ataxias frontotemporal dementia 158 parkinsonism 64 of speech 144 APTX gene 292 ARHGEF9 gene 262 ar ipiprazole 307 aromatic amino acid decarboxylase (AADC) autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) 272, 273 autosomal recessive ce rebellar ataxias benztropine 79, 169, 185, 209, 304, 305 Bereitschaft spotential (BP) 38 \200\2239, 262, (ARCAs) 282, 283, 284, 286, 292 \200\2234, 297 333, 341 autosomal recessive dystonia in gypsies 195 autosomal recessive spastic ataxia of -adrenergic antagonists 93 beta-blockers 249, 305, 321 beta-carbolines 163 Bickerstaff \200\231s encephalitis 289 bilateral striopallidodentate calcifi cation 124 bimanual moveme nts, control of 25 \200\2236 biotin 292 biperiden 169, 271, 305 bladder dysfunction