Clinical overview and phenomenology of movement disorders

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Chapter 1 Clinical overview and phenomenology of movement disorders

Fundamentals

The quotation from William Osler is an apt introduction to this chapter, which offers a description of the various phenomenologies of movement disorders. Movement disorders can be defined as neurologic syndromes in which there is either an excess of movement or a paucity of voluntary and automatic movements, unrelated to weakness or spasticity (Table 1.1). The former are commonly referred to as hyperkinesias (excessive movements), dyskinesias (unnatural movements), and abnormal involuntary movements. In this text, the term dyskinesias is used most often, but all are interchangeable. The five major categories of dyskinesias in alphabetical order are chorea, dystonia, myoclonus, tics, and tremor. Table 1.1 presents the complete list.

Table 1.1 Movement disorders

Hypokinesias

Hyperkinesias

The paucity of movement group can be referred to as hypokinesia (decreased amplitude of movement), but bradykinesia (slowness of movement), and akinesia (loss of movement) could be reasonable alternative names. The parkinsonian syndromes are the most common cause of such paucity of movement; other hypokinetic disorders represent only a small group of patients. Basically, movement disorders can be conveniently divided into parkinsonism and all other types; each of these two groups has about an equal number of patients.

Distinguishing between organic and psychogenic causation requires expertise in recognizing the various phenomenologies. Psychogenic movement disorders are covered in Chapter 25.

Those who are interested in keeping up-to-date in the field of movement disorders should refer to the journal Movement Disorders, published 12 times per year by The Movement Disorder Society, Inc. (www.movementdisorders.org). The journal, which is accompanied by two DVDs per year, comes with Movement Disorder Society membership, which is open to all interested medical professionals.

Categories of movements

It is important to note that not all of the hyperkinesias in Table 1.1 are technically classified as abnormal involuntary movements, commonly called AIMS. Movements can be categorized into one of four classes: automatic, voluntary, semivoluntary (also called unvoluntary) (Lang, 1991; Tourette Syndrome Classification Study Group, 1993; Fahn, 2005), and involuntary (Jankovic, 1992). Automatic movements are learned motor behaviors that are performed without conscious effort, e.g., walking an accustomed route, and tapping of the fingers when thinking about something else. Voluntary movements are intentional (planned or self-initiated) or externally triggered (in response to some external stimulus; e.g., turning the head toward a loud noise or withdrawing a hand from a hot plate). Intentional voluntary movements are preceded by the Bereitschaftspotential (or readiness potential), a slow negative potential recorded over the supplementary motor area and contralateral premotor and motor cortex appearing 1–1.5 seconds prior to the movement. The Bereitschaftspotential does not appear with other movements, including the externally triggered voluntary movements (Papa et al., 1991). In some cases, learned voluntary motor skills are incorporated within the repertoire of the movement disorder, such as camouflaging choreic movements or tics by immediately following them with voluntarily executed movements, so-called parakinesias. Semivoluntary (or unvoluntary) movements are induced by an inner sensory stimulus (e.g., need to “stretch” a body part or need to scratch an itch) or by an unwanted feeling or compulsion (e.g., compulsive touching or smelling). Many of the movements occurring as tics or as a response to various sensations (e.g., akathisia and the restless legs syndrome) can be considered unvoluntary because the movements are usually the result of an action to nullify an unwanted, unpleasant sensation. Unvoluntary movements usually are suppressible. Involuntary movements are often non-suppressible (e.g., most tremors and myoclonus), but some can be partially suppressible (e.g., some tremors, chorea, dystonia, stereotypies and some tics) (Koller and Biary, 1989).

The origins of abnormal movements

Many movement disorders are associated with pathologic alterations in the basal ganglia or their connections. The basal ganglia are that group of gray matter nuclei lying deep within the cerebral hemispheres (caudate, putamen, and pallidum), the diencephalon (subthalamic nucleus), the mesencephalon (substantia nigra), and the mesencephalic-pontine junction (pedunculopontine nucleus) (see Chapter 3). There are some exceptions to this general rule. Pathology of the cerebellum or its pathways typically results in impairment of coordination (asynergy, ataxia), misjudgment of distance (dysmetria), and intention tremor. Myoclonus and many forms of tremors do not appear to be related primarily to basal ganglia pathology, and often arise elsewhere in the central nervous system, including cerebral cortex (cortical reflex myoclonus), brainstem (cerebellar outflow tremor, reticular reflex myoclonus, hyperekplexia, and rhythmical brainstem myoclonus such as palatal myoclonus and ocular myoclonus), and spinal cord (rhythmical segmental myoclonus and non-rhythmic propriospinal myoclonus). Moreover, many myoclonic disorders are associated with diseases in which the cerebellum is involved, such as those causing the Ramsay Hunt syndrome of progressive myoclonic ataxia (see Chapter 20). The peripheral nervous system can give rise to abnormal movements also, such as the painful legs–moving toes syndrome (Marsden, 1994). It is not known for certain which part of the brain is associated with tics, although the basal ganglia and the limbic structures have been implicated. Certain localizations within the basal ganglia are classically associated with specific movement disorders: substantia nigra with bradykinesia and rest tremor; subthalamic nucleus with ballism; caudate nucleus with chorea; and putamen with dystonia.

Historical perspective

The neurologic literature contains a number of seminal papers, reviews and books that emphasized and established movement disorders as associated with the basal ganglia pathology (Alzheimer, 1911; Fischer, 1911; Wilson, 1912; Hunt, 1917; Vogt and Vogt, 1920; Jakob, 1923; Putnam et al., 1940; Denny-Brown, 1962; Martin, 1967).

An historical perspective of movement disorders can be gained by listing the dates when the various clinical entities were first introduced (Table 1.2).

Table 1.2 Some notable historical descriptions of movement disorders

Year Source Entity
  Bible Reference to tremor in the aged
    Trembling associated with fear and strong emotion
1567 Paracelsus Mercury-induced tremor
1652 Tulpius Spasmodic torticollis
1685 Willis Restless legs syndrome
1686 Sydenham Sydenham chorea
1817 Parkinson Parkinson disease
1825 Itard Tourette syndrome
1830 Bell Writer’s cramp
1837 Couper Manganese-induced parkinsonism
1848 Grisolle Primary writing tremor
1871 Hammond Athetosis
1871 Traube Spastic dysphonia
1871 Steinthal Apraxia
1872 Huntington Huntington disease
1872 Mitchell Jumpy stumps
1874 Kahlbaum Catatonia
1878 Beard Jumpers
1881 Friedreich Myoclonus
1885 Gilles de la Tourette Tourette syndrome
1885 Gowers Paroxysmal kinesigenic choreoathetosis
1886 Spencer Palatal myoclonus
1887 Dana Hereditary tremor
1887 Wood Cranial dystonia
1889 Benedikt Benedikt syndrome
1891 Unverricht Progressive myoclonus epilepsy (Unverricht–Lundborg disease)
1895 Schultze Myokymia
1900 Dejerine/Thomas Olivopontocerebellar atrophy
1900 Liepmann Apraxia
1901 Haskovec Akathisia
1903 Batten Neuronal ceroid lipofuscinosis
1904 Holmes Midbrain (“rubral”) tremor
1908 Schwalbe Familial dystonia
1910 Meige Oromandibular dystonia
1911 Oppenheim Dystonia musculorum deformans
1911 Lafora Lafora disease
1912 Wilson Wilson disease
1914 Lewy Lewy bodies in Parkinson disease
1916 Henneberg Cataplexy
1917 Hunt Progressive pallidal atrophy
1920 Creutzfeldt Creutzfeldt–Jakob disease
1921 Jakob Creutzfeldt–Jakob disease
1921 Hunt Dyssynergia cerebellaris myoclonica (Ramsay Hunt syndrome)
1922 Hallervorden/Spatz Pantothenate kinase deficiency (neurodegenerative disorder with brain iron deposition-1)
1923 Sicard Akathisia
1924 Fleischhacker Striatonigral degeneration
1926 Davidenkow Myoclonic dystonia
1927 Goldsmith Hereditary chin quivering
1927 Orzechowski Opsoclonus
1931 Herz Myorhythmia
1931 Guillain/Mollaret Palato-pharyngo-laryngo-oculo-diaphragmatic myoclonus
1932 De Lisi Hypnic jerks
1933 Spiller Fear of falling
1933 Scherer Striatonigral degeneration
1940 Mount/Reback Paroxysmal nonkinesigenic dyskinesia (paroxysmal dystonic choreoathetosis)
1941 Louis-Bar Ataxia-telangiectasia
1943 Kanner Autism
1944 Asperger Autism
1946 Titeca/van Bogaert Dentatorubral-pallidoluysian degeneration
1949 Alexander Alexander disease
1953 Adams/Foley Asterixis
1953 Symonds Nocturnal myoclonus (periodic movements in sleep)
1954 Davison Pallido-pyramidal syndrome (PARK15)
1956 Moersch/Woltman Stiff-person syndrome
1957 Schonecker Tardive dyskinesia
1958 Kirstein/Silfverskiold Startle disease (hyperekplexia)
1958 Smith et al. Dentatorubral-pallidoluysian degeneration
1958 Monrad-Krohn/Refsum Myorhythmia
1959 Paulson Acute dystonic reaction
1960 Ekbom Restless legs
1960 Shy/Drager Dysautonomia with parkinsonism (multiple system atrophy)
1961 Hirano et al. Parkinsonism-dementia complex of Guam
1961 Andermann et al. Facial myokymia
1961 Isaacs Neuromyotonia, Isaacs syndrome
1962 Kinsbourne Opsoclonus-myoclonus
1963 Lance/Adams Posthypoxic action myoclonus
1964 Adams et al. Striatonigral degeneration
1964 Steele et al. Progressive supranuclear palsy
1964 Levine Neuroacanthocytosis
1964 Kinsbourne Sandifer syndrome
1964 Lesch/Nyhan Lesch–Nyhan syndrome
1965 Hakim/Adams Normal pressure hydrocephalus
1965 Goldstein/Cogan Apraxia of lid opening
1966 Suhren et al. Hyperekplexia
1966 Rett Rett syndrome
1967 Haerer et al. Hereditary nonprogressive chorea
1968 Rebeiz et al. Cortical-basal ganglionic degeneration
1968 Delay/Denniker Neuroleptic malignant syndrome
1969 Horner/Jackson Hypnogenic paroxysmal dyskinesias
1969 Graham/Oppenheimer Multiple system atrophy
1970 Spiro Minipolymyoclonus
1970 Ritchie Jumpy stumps
1971 Spillane et al. Painful legs and moving toes
1975 Perry et al. Familial parkinsonism with hypoventilation and mental depression
1976 Segawa et al. Dopa-responsive dystonia
1976 Allen/Knopp Dopa-responsive dystonia
1977 Hallett et al. Reticular myoclonus
1978 Satoyoshi Satoyoshi syndrome
1978 Fahn Tardive akathisia
1979 Hallett et al. Cortical myoclonus
1979 Rothwell et al. Primary writing tremor
1980 Fukuhara et al. Myoclonus epilepsy associated with ragged red fibers (MERFF)
1980 Coleman et al. Periodic movements in sleep
1981 Fahn/Singh Oscillatory myoclonus
1981 Lugaresi/Cirignotta Hypnogenic paroxysmal dystonia
1982 Burke et al. Tardive dystonia
1983 Langston et al. MPTP-induced parkinsonism
1984 Heilman Orthostatic tremor
1985 Aronson Breathy dysphonia
1986 Bressman et al. Biotin-responsive myoclonus
1986 Schenck et al. REM sleep behavior disorder
1986 Schwartz et al. Oculomasticatory myorhythmia
1987 Tominaga et al. Tardive myoclonus
1987 Little/Jankovic Tardive myoclonus
1990 Iliceto et al. Abdominal dyskinesias
1990 Ikeda et al. Cortical tremor/myoclonus
1991c Brown et al. Propriospinal myoclonus
1991 Hymas et al. Obsessional slowness
1991 De Vivo et al. GLUT1 deficiency syndrome
1992 Stacy/Jankovic Tardive tremor
1993 Bhatia et al. Causalgia-dystonia
1993 Atchison et al. Primary freezing gait
1993 Achiron et al. Primary freezing gait
2002 Namekawa et al. Adult-onset Alexander disease
2002 Okamoto et al. Adult-onset Alexander disease

Other important dates in the history of movement disorders are 1912, the coining of the term “extrapyramidal” by Wilson; 1985, the founding of the Movement Disorder Society, and 1986, the publication of the first issue of the journal, Movement Disorders.

Epidemiology

Movement disorders are common neurologic problems, and epidemiological studies are available for some of them (Table 1.3). There have been several studies for Parkinson disease (PD), and these have been carried out in several countries (Tanner, 1994; de Lau and Breteler, 2006). Table 1.3 lists the prevalence rates of some movement disorders based on studies in the United States. The frequency of different types of movement disorders seen in the two specialty clinics at Columbia University and Baylor College of Medicine are presented in Table 1.4. More detailed information is provided in the relevant chapters for specific diseases.

Table 1.3 Prevalence of movement disorders

Disorder Rate per 100 000 Reference
Restless legs 9800* Rothdach et al. (2000)
Essential tremor 415 Haerer et al. (1982)
Parkinson disease 187 Kurland (1958)
Tourette syndrome 29–1052 Caine et al. (1988), Comings et al. (1990)
  2990 Mason et al. (1998)
Primary torsion dystonia 33 Nutt et al. (1988)
Hemifacial spasm 7.4–14.5 Auger and Whisnant (1990)
Blepharospasm 13.3 Defazio et al. (2001)
Hereditary ataxia 6 Schoenberg (1978)
Huntington disease 2–12 Harper (1992), Kokmen et al. (1994)
Wilson disease 3 Reilly et al. (1993)
Progressive supranuclear palsy 2 Golbe (1994)
  2.4 Nath et al. (2001)
  6.4 Schrag et al. (1999)
Multiple system atrophy 4.4 Schrag et al. (1999)

Rates are given per 100 000 population. *For restless legs, the rate cited is in a population 65–83 years of age. For Parkinson disease, the rate is 347 per 100 000 for ages over 39 years (Schoenberg et al., 1985).

Table 1.4 The prevalence of movement disorders encountered in two large movement disorder clinics

Movement disorder Number of patients Percent
Parkinsonism 15 107 35.3
Parkinson disease 10 182  
Progressive supranuclear palsy 750  
Multiple system atrophy 841  
Cortical-basal ganglionic degeneration 297  
Vascular 867  
Drug-induced 327  
Hemiparkinsonism–hemiatrophy 116  
Gait disorder 329  
Other 1 308  
Dystonia 10 394 24.3
Primary dystonia 7 784  
Focal   (59%)
Segmental   (29%)
Generalized   (12%)
Secondary dystonia 6 610  
Hemidystonia 279  
Tardive 595  
Other 1 737  
Tremor 6 754 15.8
Essential tremor 2 818  
Cerebellar 205  
Midbrain (“rubral”) 88  
Primary writing 114  
Orthostatic 82  
Other 1 035  
Tics (Tourette syndrome) 2 753 6.4
Chorea 1 225 2.9
Huntington disease 690  
Hemiballism 123  
Other 412  
Tardive syndromes 1 253 2.9
Myoclonus 1 020 2.4
Hemifacial spasm 693 1.6
Ataxia 764 1.9
Paroxysmal dyskinesias 474 1.1
Stereotypies (other than TD) 246 0.6
Restless legs syndrome 807 1.9
Stiff-person syndrome 70 0.2
Psychogenic movement disorder 1 268 3.0
Grand total 42 826 100

The above data were obtained from the combined databases of the Movement Disorder Clinics at Columbia University Medical Center (New York City) and Baylor College of Medicine (Houston) for patients encountered through April 2009. Because some patients might have more than one type of movement disorder (such as a combination of essential tremor and Parkinson disease), they would be listed more than once. Therefore, the figures in the table represent the types of movement disorder phenomenology encountered in two large clinics, rather than the exact number of patients.

Genetics

A large number of movement disorders are genetic in etiology, and many of the diseases have now been mapped to specific regions of the genome, and some have even been localized to a specific gene (Table 1.5). For example, ten genetic loci have so far been identified with Parkinson disease (PD) or variants of classic PD (PARK4 is a triplication of the normal α-synuclein gene, for which mutations are listed as PARK1). Several genetic loci of movement disorders have been identified with a specific gene and protein. A comprehensive list of movement disorders whose genes have been mapped or identified are listed in Table 1.5. A detailed chapter (Harris and Fahn, 2003) and an entire book (Pulst, 2003) have been published specifically related to movement disorder genetics. Several inherited movement disorders are due to expanded repeats of the trinucleotide cytosine-adenosine-guanosine (CAG), and Friedreich ataxia is due to the expanded trinucleotide repeat of guanosine-adenosine-adenosine (GAA). Normal individuals contain an acceptable number of these trinucleotide repeats in their genes, but these triplicate repeats are unstable, and when expanded, lead to disease (Table 1.6). Neurogenetics is one of the fastest moving research areas in neurology, so the list in Table 1.5 keeps expanding rapidly.

Quantitative assessments

The assessment of severity of disease is a process that is carried out by all clinicians when evaluating a patient. Quantifying the severity provides the means of determining the progression of the disorder and the effect of intervention by pharmacologic or surgical approaches. Many mechanical and electronic devices, including accelerometers, can quantitate specific signs, such as tremor, rigidity, and bradykinesia. These have been developed by physicians and engineers over at least 80 years (Lewy, 1923; Carmichael and Green, 1928), and newer computerized devices continue to be conceived and developed (Larsen et al., 1983; Tryon, 1984; Potvin and Tourtelotte, 1985; Cohen et al., 2003). The advantages of mechanical and electronic measurements are objectivity, consistency, uniformity among different investigators, and rapidity of database storage and analysis. However, these measurements might not be as sensitive as more subjective clinical measurements. In one study comparing objective measurements of reaction and movement times with clinical evaluations, Ward and his colleagues (1983) found the latter to be more sensitive.

The mechanical and electronic methods of measurement have other disadvantages. Instrumentation can usually measure only a single sign, at a single point in time, and in a single part of the body. Disorders such as parkinsonism encompass a wide range of motor abnormalities, as well as behavioral features. Clinical measurements can cover a wider range of the parkinsonian spectrum of impairments, and have the advantage of being carried out at the bedside or in the office or clinic at the time the patient is being examined by the physician. Equally important, clinical assessment can evaluate disability in terms of activities of daily living (ADL), and the one developed by England and Schwab (1956) and modified slightly (Fahn and Elton, 1987) has proven highly useful.

A number of clinical rating scales have been proposed (e.g., see Marsden and Schachter, 1981). Several that are now considered standards and are in wide use can be recommended: the Unified Parkinson’s Disease Rating Scale (UPDRS) (Fahn and Elton, 1987) is the standard scale for rating severity of signs and symptoms; a videotaped demonstration of the assigned ratings has been published (Goetz et al., 1995). A modification of the UPDRS by the Movement Disorder Society is underway (Goetz et al., 2007) and will be known as the MDS-UPDRS. Other standard scales for PD and its complications are the Schwab and England Activities of Daily Living scale for parkinsonism (Schwab and England, 1969) as modified (Fahn and Elton, 1987); the Hoehn and Yahr Parkinson Disease Staging Scale (Hoehn and Yahr, 1967) as modified (Fahn and Elton, 1987); the Goetz dopa dyskinesia severity scale (Goetz et al., 1994); the Lang–Fahn dopa dyskinesia ADL scale (Parkinson Study Group, 2001); the Parkinson psychosis scale (Friedberg et al., 1998); the daily diary to record fluctuations and dyskinesias (Hauser et al., 2004); the core assessment program for intracerebral transplantation (Langston et al., 1992); the PSP Rating Scale (Golbe and Ohman-Strickland, 2007); the Fahn–Marsden Dystonia Rating Scale (Burke et al., 1985); the Unified Dystonia Rating Scale (Comella et al., 2003); the Fahn–Tolosa clinical rating scale for tremor (Fahn et al., 1993); the Bain tremor scale (Bain et al., 1993); and the Unified Huntington’s Disease Rating Scale, which also has a published videotaped demonstration of assigned ratings (Huntington Study Group, 1996).