Akinetic rigid syndrome: causes, symptoms, diagnosis

The term "hypokinesia" (akinesia) can be used in a narrow and broader sense.

In a narrow sense, hypokinesia refers to an extrapyramidal disorder in which the inconsistency of movements is manifested in their insufficient duration, speed, amplitude, a decrease in the number of muscles involved in them and the degree of diversity of motor acts.

In a broad sense, hypokinesia denotes a more or less prolonged limitation of general motor activity of any other origin. Such hypokinesia is inevitably caused by many neurological disorders: monoparesis (in the legs), hemi-, para- and tetraparesis, severe gait disturbances due to ataxia, apraxia or a sharp increase in muscle tone. Hypokinesia in this sense is characteristic of depression, catatonia, and some psychogenic movement disorders. Finally, its origin may also be purely physiological (hypokinesia caused by external environmental requirements or one's own motives). Neurological interpretation of hypokinetic syndrome always requires taking into account many possible causes of hypokinesia and conducting a syndromic differential diagnosis, which sometimes appears to be an extremely difficult diagnostic task. The term "rigidity" is also not unambiguous. It is enough to recall such commonly used terminology as "extrapyramidal rigidity" (the most frequently used meaning of the word "rigidity"), "decerebrate rigidity and decorticate rigidity"; the term "stiffness" (muscle tension of spinal or peripheral origin) is also translated by many domestic and foreign neurologists as rigidity. In Russian, there is no generally accepted synonym for this term. Recognizing the true nature of "rigidity" is no less complex a task than clarifying the nature of hypokinesia.

The term “akinetic-rigid syndrome” is used in a narrow sense, as a synonym for the extrapyramidal phenomenon of “parkinsonism”.

The initial stages of Parkinsonism, contrary to popular belief, are extremely difficult to diagnose. Unfortunately, some publications do not quite accurately describe the diagnostic criteria for Parkinsonism syndrome.

A diagnosis of true Parkinsonism syndrome requires the presence of hypokinesia plus at least one of three other symptoms: muscle rigidity, low-frequency resting tremor, or postural disturbances.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ], [ 7 ], [ 8 ]

The main causes of akinetic-rigid syndrome:

• Parkinson's disease
• Strio-nigral degeneration
• Shaya-Drager syndrome
• OPCA (sporadic form)
• Progressive supranuclear palsy
• Juvenile form of Huntington's chorea
• Wilson-Konovalov disease.
• Hepato-cerebral syndromes
• Parkinsonism - ALS - Dementia
• Senile encephalopathy
• Normal pressure hydrocephalus
• Calcification of the basal ganglia
• Storage diseases
• Corticobasal degeneration
• Chronic intoxications (including drug-induced)
• Atrophic processes in the brain (including Alzheimer's and Pick's diseases)
• Space-bounding processes
• Post-traumatic
• Postencephalitic
• Vascular
• Segawa disease
• Creutzfeldt-Jakob disease
• Rare forms of multiple sclerosis and leukoencephalitis
• Hypoxic encephalopathy (including "disease of the revived brain").
• Hereditary dystonia-parkinsonism with rapid onset.
• Diffuse Lewy Body Disease
• Spinocerebellar degenerations
• Mitochondrial encephalomyopathy
• Neuroacanthocytosis
• Hereditary X-linked dystonia-parkinsonism.
• HIV infection
• Neurosyphilis
• Hypothyroidism
• Hypoparathyroidism
• Hereditary taurine deficiency
• Syringomesencephaly
• Hemiparkinsonism-hemiatrophy syndrome.

Since approximately 80% of all cases of Parkinsonism syndrome are idiopathic Parkinsonism, i.e. Parkinson's disease, knowledge of modern diagnostic criteria for Parkinson's disease already ensures correct recognition of the etiology of most cases of Parkinsonism. The generally accepted diagnostic criteria for Parkinson's disease suggest a three-stage diagnosis:

• Stage 1 - recognition of Parkinsonism syndrome,
• Stage 2 - search for symptoms that exclude Parkinson's disease and
• Stage 3 – identification of symptoms confirming Parkinson’s disease.

Diagnostic criteria for Parkinson's disease (based on: Hughes et al., 1992)

Exclusion criteria for Parkinson's disease:

• History of recurrent strokes with stepwise progression of Parkinsonism symptoms, recurrent traumatic brain injury, or proven encephalitis.
• Oculogyric crises.
• Treatment with neuroleptics before the onset of the disease.
• Long-term remission.
• Strictly one-sided manifestations for more than 3 years.
• Supranuclear gaze palsy.
• Cerebellar signs.
• Early onset of symptoms of severe autonomic failure.
• Early onset of severe dementia.
• Babinski's sign.
• The presence of a cerebral tumor or open (communicating) hydrocephalus.
• Negative reaction to large doses of L-DOPA (if malabsorption is excluded).
• MPTP (methyl-phenyl-tetrahydropyridine) intoxication.

Confirmatory criteria for Parkinson's disease. Three or more criteria are needed for a reliable diagnosis of Parkinson's disease:

• Unilateral onset of disease manifestations.
• Presence of resting tremor.
• Permanent asymmetry with more pronounced symptoms on the side of the body where the disease began.
• Good response (70-100%) to L-DOPA.
• Progressive course of the disease.
• The presence of severe dyskinesia induced by L-DOPA.
• Response to L-DOPA for 5 years or more.
• Long-term course of the disease (10 years or more).

Negative criteria are important because they remind the physician to rule out Parkinson's disease if the patient, for example, does not respond to treatment with L-DOPA, has early development of dementia or early postural disturbances and falls, etc.

In progressive supranuclear palsy, only downward movements of the eyeballs are impaired in the initial stage of the disease (and only then their upward and sideways movements). The phenomenon of "doll's eyes and head" is formed (impairment of voluntary gaze movements with preservation of reflex movements). Dystonic rigidity of the neck and upper body with a characteristic extensor position of the head is revealed. General moderate hypokinesia is quite typical; pseudobulbar syndrome; dysbasia with spontaneous falls; cognitive impairment. Pyramidal and cerebellar symptoms are possible. Dopa-containing drugs are not effective.

Due to the practical significance of the diagnosis of vascular parkinsonism (its overdiagnosis is often observed), we will mention the principles of its diagnosis.

A necessary condition for the diagnosis of vascular parkinsonism is the presence of a vascular disease of the brain (hypertension, arteriosclerosis, vasculitis), confirmed by CT or MRI data (multiple lacunar infarctions, less often a single contralateral infarction, Binswanger's disease, expansion of perivascular spaces, amyloid angiopathy, etc.). Subacute or acute onset of the disease is characteristic (but can also be gradual), fluctuating course, the presence of symptoms of cerebrovascular insufficiency (pyramidal, pseudobulbar, cerebellar, sensory, mental disorders), predominance of parkinsonism symptoms in the lower half of the body, gross dysbasia, absence of tremor, non-response to dopa-containing drugs (as a rule).

Binswanger's disease is often accompanied by symptoms that only resemble Parkinsonism, but the development of a true Parkinsonism syndrome is also possible.

The main syndromes of movement disorders resembling parkinsonism ("pseudoparkinsonism"), sometimes requiring differential diagnosis with true parkinsonism

In clinical neurology, syndromic diagnosis precedes topical and etiologic diagnostics. Recognition of parkinsonism syndrome primarily involves differential diagnosis with pseudoparkinsonism. Pseudoparkinsonism is a conventional and collective term that in this context unites a group of neurological and psychopathological syndromes that are not related to parkinsonism, but sometimes resemble it in certain clinical manifestations. Such clinical manifestations may include psychomotor retardation, muscle tension (stiffness), gait apraxia, and some other neurological syndromes.

The diagnosis of "pseudoparkinsonism" is thus purely operational, intermediate, didactic and is made if the observed clinical picture does not correspond to the criteria of the syndromic diagnosis of true parkinsonism. The final syndromic diagnosis requires the indication of a specific form of pseudoparkinsonism:

Psychomotor retardation syndromes:

1. Depressive stupor.
2. Catatonic stupor.
3. Organic stupor.
4. Hypersomnia.
5. Hypothyroidism.
6. Hypo- and hyperthyroidism.
7. Psychogenic parkinsonism.

Muscle tension syndromes (Stiffness):

1. Isaacs' Armadillo Syndrome.
2. Rigid person syndrome.
3. Progressive encephalomyelitis with rigidity (spinal interneuronitis).
4. Schwartz-Jampel syndrome.
5. Muscle tension syndromes with damage to peripheral nerves.
6. Dystonia.

Gait apraxia syndromes:

1. Normal pressure hydrocephalus.
2. Progressive supranuclear palsy.
3. Other degenerative-atrophic processes in the brain.
4. Processes that limit space (tumors, subdural hematoma).
5. Post-traumatic encephalopathy.
6. Lacunar condition.
7. Isolated gait apraxia syndrome.

Mixed syndromes:

1. Locked-in syndrome.
2. Akinetic mutism syndrome.
3. Rigid spine syndrome.
4. Painful Leg and Moving Toes Syndrome.
5. Neuroleptic malignant syndrome.
6. Malignant hyperthermia syndrome.
7. Idiopathic senile dysbasia.