Praha & EU: Investujeme do vaší budoucnosti Evropský sociální fond. Principles of general neurology

Praha & EU: Investujeme do vaší budoucnosti Evropský sociální fond

Principles of general neurology


The 1st week Mon - Wed General neurology Thur Paediatric neurology Fri Disorders of consciousness The 2nd week Mon Strokes Tue Parkinson´s disease and syndromes Wed Dyskinesias Thur Epilepsy Fri Meningitis, encephalitis, myelitis, radiculoneuritis


The 3rd week Mon Neuromuscular diseases and neuropathies Tue Neuro-oncology Wed Traumatic brain injuries, spinal cord injuries Thur Multiple sclerosis Fri Spinal disorders and basic compression syndromes of peripheral nerve The 4th week Mon Sleep disorders Tue Pain Wed Dementia Thur Paediatric neurology Fri Propedaedeutic examination + EXAM


Lectures http://www.neuro.lf1.cuni.cz/eng/vyuka/in dex.php?page=prezentace_5r

Diagnostic algortihm Praha & EU: Investujeme do vaší budoucnosti Evropský sociální fond

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Medical history

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Neurological examination

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Interpretation of acquired data - formulating clinical suspicion

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Indication of relevant auxiliary investigative techniques with clearly formulated presumption Exception: traumatic injury, altered consciousness


Interpretation of acquired data formulating clinical suspicion

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Syndromologic (semiologic) diagnosis: summary of individual symptoms/signs of disease clustered in characteristic combination

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Topical diagnosis: level of lesion within the neural systém

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Nosological diagnosis: clinical entity (disease) characterized by neurological syndrome, along with clinical course, treatment response etc.

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Etiological diagnosis: cause of neural lesion, often special targeted examination methods are necessarily indicated


Basic terms

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Symptom: individual presentation

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Syndrome: 2 a more symptoms present together in an individual in characteristic combination (important for topology, e.g. parkinsonian syndrome – lesion of basal ganglia, or for pathogenesis, e.g. meningism indicates inflammation of meninges)

Basic terms Praha & EU: Investujeme do vaší budoucnosti Evropský sociální fond

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Paresis: decrease in muscular strength, partial paralysis Plegia: loss of muscle strength, complete paralysis monoparesis: one limb affected  diparesis: 2 limbs affected  triparesis: 3 limbs affected  quadriparesis: all limbs affected 

hemiparesis: limbs of one body side affected (left / right)  paraparesis: both lower limbs affected 


Basic terms

Superficial sensation - algic and thermic (spinothalamic pathway): • algic - pain • thermic – heat, cold

Superficial sensation - tactile (posterior funicles and spinothalamic pathway): • tactile – touch, dicriminative...

Deep sensation (posterior funicles): • pallesthesia = capability of sensing vibrations • proprioception, kinesthesia =capability of sensing position, direction and changes of movement speed


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Basic terms

anesthesia: complete loss of sensation in respective body part hypesthesia: reduced sensationi hyperesthesia: enhanced sensation paresthesia: abnormal somatosensory perception in absence of external stimulus (spontaneous pins and needles, freezing, burning etc.) dysesthesia: erroneous perception of real somatosensory stimulus (touch as burning, heat as cold etc.) allodynia: painful sensation induced by stimulus that is not usually associated with pain


Peripheral and central nervous system


Levels of peripheral nervous system

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Muscle

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Neuromuscular junction

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Peripheral nerve (motor-sensitive-mixed)

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Plexus

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Roots: (dorsal root, ventral root, combined root lesion)

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Peripheral (caudal) motor neuron


Levels of central nervous system

Spinal cord  Brain 

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Infratentorial area

-brainstem -cerebellum

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Supratentorial area

-white matter of hemispheres -thalamus -basal ganglia -cortex


Basal differences between peripheral and central lesion

Parameter

Peripheral lesion

Central lesion

Deep tendon reflexes Muscle tone

Pyramidal signs

-

+

Disordered sensation + (radic. area, nerv.)

+ (large regions)

Muscle atrophy

+

-

Fasciculations

+

-

Muscle weakness

+(radic. area, nerv.)

(late, from inactivity) + (large regions)


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Peripheral lesion – flaccid paresis

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Central lesion - spastic paresis 

Pseudoflaccid stage: first 2-3 weeks after acute lesion of pyramidal pathways hypotonia and areflexia (parallel to spinal shock)


Peripheral lesion


Muscle lesion – clinical characterization

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Muscle weakness (localization depends on distribution of affected muscles, more often proximal)‫‏‬

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atrophy, hypotrophy, pseudohypertrophy



hypotonia

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reduced (but may be also adequate) stretch proprioceptive reflexes



absent disorder of sensation but pain may be present (myositis, rhabdomyolysis)‫‏‬

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(myopatic climb)‫‏‬


Disorders of neuromuscular junction (myasthenic pattern)‫‏‬

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muscular fatigue, weakness depending on preceding physical effort



no sensory deficit



no pain



normal muscle tone

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normal proprioceptive reflexes

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normal muscle mass (-trophy)


Lesion of peripheral nerve

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muscle weakness in „area nervina“ distribution



disorder of sensation in „area nervina“ or „glove-like, sock-like“ distribution (not always present – depends whether the nerve with sensitive component is affected)



Pain may be present


Areae nervorum


Areae nervorum


Diffuse lesion of peripheral nerves 

muscle weakness that doesn´t correspond to particular area nervina (most often acral localization) frequently present after sensation disorder



altered sensation in „glove-/sock-like“ distribution (not always present – depends on the fact whether the nerve with sensitive component is affected)



pain may be present

Etiology: diffuse lesion (inflammatory, metabolic…)


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Lesion of plexus

Muscle weakness and hypotonia Altered sensation in distribution noncorresponding to area nervina, radicularis (larger, several segments)

Radicular lesion Praha & EU: Investujeme do vaší budoucnosti Evropský sociální fond

Lesion of dorsal root  sensory disorder  pain in distribution of area radicularis  no muscle weakness  no fasciculations Lesion of ventral root  muscle weakness in distribution of area radicularis  fasciculation  no sensory disorder  no pain Lesion of lower motor neuron  muscle weakness and hypotonia in distribution of damaged neurons – otherwise identical to ventral root lesion


Radicular lesion

Sensory neurons  dorsal root  Innervated skin area = dermatome 

alpha motor neurons in anterior horns of spinal cord– axons form ventral root  project through plexus and peripheral nerves into muscle groups = myotome




Chipault´s rule

Spines of upper C vertebrae lower C vertabrea upper Th vertabrae lower Th vertebra Th10-Th12 Trans.: Th12-L1 vertebra L1 -

Segment identical +1 +2 +3 L epiconus conus

Diagram of root exit points


Syndrome of cauda (common in prolapsed disc)‫‏‬



Irritative  Severe pain in assymetric radicular distribution



Destructive  Assymetric disorder of sensation - radicular distribution  Areflexia (corresponding to affected roots)‫‏‬  Weakness (corresponding to affected roots)‫‏‬  Sphincter disturbance


MRI sequestrum

CT prolapse


Syndrome of conus, epiconus: vertebral body level: Th12-L1



Conus (S3-5) – often tumor, traumatic injury  Altered perianogenital sensation  Urinary retention, fecal incontinence  Erectile dysfunction  No marked pain  Bilateral symmetric presentation



Epiconus  The same as in conus  +weakness of plantar, dorsal flexion of foot, areflexia L5-S2


conus, epiconus


Central lesion – spinal cord


Image of spinal cord


General characteristics of spinal cord lesions



Lesion of spinal cord

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Motor disorders  Peripheral paresis in affected segment  Central paresis under the affected segment



Posture stability and gait disturbances

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Altered sensation



Sphincter dysfunction (retention or incontinence)



Backache and constrictive sensations in certain segments


Transversal lesion of spinal cord



Plegia distally from the localization of lesion (Acute: spinal shock – plegia - hypotonia, absent pyramidal signs etc. - duration: hours to weeks) Combined with peripheral paralysis according to localization (Lesions above C5 are not compatible with life without artificial ventilation.)



Anesthesia distally from the localization of lesion (sometimes hyperesthesia on the margin of anesthesia) !Margin of sensation!



Sphincter dysfunctions Acute: Retention of urine or paradoxical ischuria Chronic: automatic (spinal) bladder


SPINAL SYNDROMES: central cord syndrome :


 

 

Central cord syndrome The most common causes: traumatic injury, tumor or ischemia. Basic characterization – Bilateral disruption of algic, heat and cold sensitivity within affected segments, with continual spread in caudal direction, usually with sacral preservation. 



Focal spinal cords pathologies

Syringomyelic dissociation of sensitivity

Later – development of peripheral paresis on the level of affected segments (lesion of motor neurons).


Diagram of sensitive pathways


syringomyelia


Intramedular tumor


 

 

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Focal pathologies of spinal cord

anterolateral syndrome The most common cause: ischemia. Basic characterization – Peripheral paresis on the level of affected segments. Central paresis caudally from lesion level - results from lesion of descendent pathways. Sensation of heat, cold and algic stimuli is affected. Preserved tactile and deep sensory functions.


Image of anterolateral lesion.


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Focal pathologies of spinal cord

Brown-Sequard´s syndrome (unilateral) The most common cause: traumatic injury. Basic characterization: On the homolateral side:  Peripheral paresis on the level of lesion  central paresis below the lesion  Sensory disturbance – deep and tactile

On the contralateral side:  No motor disorder  Disrupted sensory f. – heat, cold, algic (incipient typically on the level lower by 2-3 segments)


Diagram of Brown.Séquard´s syndrome


Posterior column syndrome (tabic syndrome)

The most common cause: neurosyphilis, metabolic diseases (diabetes mellitus) Basic characterization  No paresis  Ataxia, areflexia  Loss of deep and also (partially) tactile sensory functions - below the lesion level.  Algic and thermic sensory functions are preserved – but with common occurence of paresthesias and shooting pains.


Posterior and lateral columns syndrome

The most common cause: Friedreich´s disease, other degenerative diseases, deficiency of vit. B12. Basic characterization:  central (spastic) paresis, characteristic spasticatactic gait  ataxia (from disruption of proprioception and cerebellar ataxia from lesion of spinocerebellar pathways)  Disruption of deep and tactile sensory functions.  Preserved algic and thermic sensory f.


Expansive process arising from the bone and compressing spinal cord.


  

Identification of lesion level

Patient with paraparesis of the lower limbs L2-S2 increased, C5-8 normal  i.e.: lesion above L2 and under C8 More precise identification:  Limit margin of sensory changes  Event. Calculation according to Chippault´s rule



Patient with peripheral paresis of the upper limbs and central paresis of the lower limbs  lesion C5-8

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Patient with central quadriparesis without lesion of cranial nerves  C1-C4 (C4-phrenic n. – threatening of vital f.)


Central lesions – the brain


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Cerebral lesions – clinical characterization

General presentation headache altered consciousness generalized epileptic paroxysms intracranial hypertension Focal signs focal neurological deficit focal epileptic paroxysms affected cranial nerves speech disturbances and other cognitive dysfunctions


Infratentorial region



Clinical characterization

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Lesion of cranial nerves Altered consciousness Alternating pattern of hemiparesis or sensory disturbance (peripheral lesion of cranial nerves on the contralateral side to hemiparesis) Hemi- or quadri-paresis, sensory disturbance

 



   

Nausea, vomiting, vertigo Nystagmus Disorder of posture, stability and gait Disruption of upper limb coordination




Brainstem localization of motor pathway: alternating hemiplegias/paresis (hemiplegiae alternantes)‫‏‬

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Mesencephalon (n. III): superior alternating hemiplegia (Weber)

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Pons (n. VI a VII): middle alternating hemiplegia (Millard-Gubler)

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Oblongata (n. XII): inferior alternating hemiplegia (Déjerine)


alternating hemiparesis


Bulbar syndrome

Lesion of nuclei of nn. IX. – XII. bilaterally (+ V. a VII.)‫‏‬ Dysarthria, dysphagia Lingual atrophy with fasciculations, depression of soft palate, extinct gag reflex, extinct masseter r. (+ paresis of facial muscles)‫‏‬


Pseudobulbar syndrome

Bilateral lesion of corticonuclear (corticobulbar) pathway heading to motor nuclei of nn. IX. – XII. Dysphagia, dysarthria

Tongue without atrophy, fasciculations Present masseter r., gag r. +‫‏‬emotional‫‏‬signs:‫„‏‬spastic“ laughter and cry


Peripheral paresis of facial nerve Lesion of peripheral nerve anywhere within its length

Paresis or plegia of the whole homolateral half of the face Smoothed wrinkles on the forehead and inability to close the eye Smoothed nasolabial sulcus and drooping mouth corner

Etiology: passage of facial nerve through petrose bone, often viral etiology Above the branching of chorda tympani – hypogeusia on anterior 2/3s of tongue Above the branching of stapedius n. – hyperacusia


Central paresis of facial nerve

Supranuclear lesion of corticobulbar pathway

Paresis of facial muscles in the lower half of the face, contralaterally:    

Drooping of the corner of the mouth Smoothed nasolabial sulcus Disruption of showing teeth, whistling Weakness of platysma

Etiology: frequent presentation of stroke on the contralateral side



Syndrome of pontocerebellar angle 

Hypacusis, tinnitus, vertigo

Peripheral paresis of n. VII.  Unilateral extinction of corneal r. 



Cerebellar syndrome

Etiology: Schwannoma of n. VIII., meningiomas


Neurinoma of n. VIII


Cerebellum

Physiological functions 

Regulation of muscle tone



balance



Movement coordination 

Movement course and targeting, positioning of body segments, recruitment of muscle groups during the movement


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

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Structure and functions of cerebellum

Archicerebellum (pars floculonodularis)‫‏‬  vestibular afferents - balance Paleocerebellum (vermis, tonsils, anterior lobe)‫‏‬  Spinal afferents – muscle tone Neocerebellum (most of hemispheres)‫‏‬  Cortical afferents – movement coordination


Paleocerebellar syndrome

Axial ataxia (axial disequilibrium)‫‏‬ 

astasia – uncertain standing with wide basis, deviations, falls without side preference



abasia – uncertainty when walking, widen basis, deviations, falls without side preference



large asynergy – dysfunction of axial muscles coordination – improper measuring of movements during standing up, sitting, rising

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titubation – swaying tremor of the head and upper trunk

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dysarthria


Neocerebellar syndrome

Limb ataxia, ipsilateral to affected cerebellar hemisphere 

hypermetria



dysdiadochokinesis



little asynergy



intention tremor



hypotonia – increased passiveness, excursion range of joints




Vestibular apparatus

Physiological functions 

Balance






Coordination of movements of the head and eyes


Inner ear: function and structure Hearing Cochlea: Corti´s organ

Balance vestibule: saccule, utricle and 3 semicircular canals with with wide ampullas – registrate changes of head position in the gravitational field and linear acceleration

Hairy cells react to movements of endolymph, to gravity or to acoustic vibrations


Saccule, utricle: Changes of head position in gravitational field, linear acceleration.

Hairy cells are located in maculas of saccule and utricle. In maculas are located so-called otoliths crystals of calcium carbonate that bend the cilia during change of head position by the effect of gravity.




Subjective symptoms: 



Vestibular syndromes

vertigo, nausea

Objective signs: Nystagmus  Balance disorder  Tonic deviations of the trunk and limbs 


Nystagmus

Involuntary fast movements of both eyeballs with slow (pathological) and fast (compensatory) component. Nystagmus results from disruption of vestibular system and its neural connections.

Direction Determined by fast component (horizontal, rotational, vertical, combined etc.) Intensity I. grade: present only when looking in direction of the fast component II. grade: apparent in forward gaze as well III. grade: persisting even when looking on the opposite side


Peripheral – harmonic vestibular syndrome

Logical relation of nystagmus direction to the direction of tonic vestibular deviations (fast component of nystagmus tends against direction of deviations)‫‏‬ Tonic deviations depend on the head position

Concomitant symptoms: often hypacusis and tinnitus Nystagmus type: horizontal rotational, doesn´t change the direction Level of lesion: Labyrinth Vestibular n. in the petrose bone, pontocerebellar angle Entrance areas of vestibular nuclei Etiology: BPPV, labyrinthitis, Menier´s disease etc.


Central - dysharmonic vestibular syndrome

The direction of nystagmus and that of tonic deviations are not logically related. E.g. only nystagmus with vertigo and minimal stability disorder may dominate Nystagmus may be in the same direction as tonic vestibular deviations. Frequent changes of direction and intensity. Accompanying symptoms: sometimes other brainstem sy Type of nystagmus: simply rotational, vertical, diagonal etc. Level of lesion: brainstem (FLM) and vestibular cerebellum

Etiology: demyelination, vascular, parainfectious


Differentiation between peripheral and central vestibular syndrome Peripheral

Central

(harmonic)

(dysharmonic)

Intensity of vertigo

high

mild, moderate

Nystagmus

one direction

changes direction

Tonic deviation

one direction

variable direction

Compensation

relatively fast

slow, difficult

Other symptoms

auditory

brainstem


Supratentorial region of the brain


Supratentorial region

Cortex 

  

 

Disorders of speech (frontal and temporal lobes) Disorders of practic and gnostic functions (parietal lobes) Behaviour disorders (prefrontal areas of frontal lobes, temporal lobes) hemianopsia (occipital lobes) epileptic paroxysms (character of paroxysm depends on the localization of focus) Pareses and sensory disorders (area of central sulcus)

Long pathways  



Sy of internal capsule (capsula interna) Hemiparesis Hemi-distributed sensory disorders


Diagram of internal capsule Praha & EU: Investujeme do vaší budoucnosti Evropský sociální fond


Lesions of internal capsule - symptoms Contralateral spastic hemiplegia/paresis including nn. XII a VII. (Wernicke-Mann´s type)‫‏‬ Contralateral hemianopsoa Contralateral hemianesthesia

(Bilateral lesion: pseudobulbar syndrome in the F portion: spastic laughter and cry and pseudocerebellar symptoms)‫‏‬



Basal ganglia

caudate nc.  putamen  gl. pallidus  subthalamic nc.  ncl. accumbens  ncl. basalis Meynerti 

related nuclei:  amygdala  thalamus  subst. nigra  ncl. ruber  pedunculopontine nc.


Basal ganglia – functional connections

Major neurotransmitters:  Dopamine  Glutamate  GABA  Acetylcholine  Neuropeptides  and others


Basal gangla – major functions 

Body posture

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Coordination of voluntary and automatic movements 

Creating movement programs, triggering and timing movements, adjustment of movements to external conditions

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emotionality, cognitive functions, mental integration


Extrapyramidal syndromes 

Hypokinetic (parkinsonian, hypokinetic-rigid, hypokinetic-hypertonic)



Hyperkinetic 

tremor



chorea



dystonia



myoclonus



tic


 

Thalamus

„Rellay‫‏‬station“ – last information interlink before entrance to cortex Integration of sensory, motor, vegetative neural activity

Dominating symptoms depend on the localization within thalamus  Motor disorders: ataxia, tremor, dystonia



Sensory disorders: hemihypesthesia, anaesthesia dolorosa Thalamic pain;



Altered consciousness

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Emotional changes, memory disturbances




Cortex

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Primary cortical centres

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Secondary association areas (unimodal association cortex)

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Tertiary association areas (multimodal association areas)  Posterior parietal area (perception and speech)  Limbic area (emotions and memory)  Anterior (prefrontal) area (planning of movements)




Disruptions of cortical areas 

Primary sensory areas  local anesthesia   amaurosis   deafness 



Primary motor areas 

 plegia, paresis


Disorders of associative cortical areas 

Unimodal and multimodal association areas Gnostic functions  agnosia Practic functions

 apraxia

Phatic functions

 aphasia


Disorders of language and speech

language – system of expression and communication means of symbolic character speech – motor production of verbal sounds  Acquired neurogenic disorders of using language aphasia, cognitive communication disorder (in dementia)‫‏‬ Acquired neurogenic disorders of speech – dysarthria, speech apraxia Diagnosis and therapy of language and speech disorders - logopedy


Aphasia



Acquired disorder of language (stroke in the territory of internal carotid a., tumor, traumatic head injury)



Focal lesion of brain



Lesion especially in cortical areas (or event. in subcortical areas - thalamus and basal ganglia)



Lesions of dominant hemisphere


Classification of aphasia (fluent speech) – formerly „sensory aphasia“- posterior lesion - behind central sulcus

 Fluent

formerly „motor“ aphasia - anterior lesion - in front of central sulcus

 Nonfluent–

aphasia (formerly „mixed“)– caused by extensive lesion of dominant hemisphere

 global



Boston classification – the most used classification of aphasia in the world; enables to classify more than ¾ of aphasias


Symptoms of aphasia

  

  

Disordered speech fluency Disordered comprehension Disordered naming Disordered repeating Perseverations Disorders of reading, writing


Symptoms of aphasia alexia – disorders of reading  agraphia – disorders of writing 



Disorder of loud reading (often similar symptoms as in spontaneous speech)



Disorder of understanding the text



Disorders of reading and writing may occur also separatedly without aphasia


Dysarthria

Disorders of speech (disorders of comprehension, naming, forming sentence structure or using grammar are not present…) 




Dysarthria

results from:  paresis  disrupted muscle tone  disordered coordination of muscles involved in speech production  lesion

of motor system leading to dysarthria – anywhere along the pathway – from the brain to the particular muscle.  Contrary from aphasia – not primarily cortical disorder!


Dysarthria



cerebellar (atactic)  Lesion of cerebellum and its pathways



extrapyramidal-hypokinetic  Lesions of basal ganglia, extrapyramidal pathways

Praha & EU: Investujeme do vaší budoucnosti Evropský sociální fond. Principles of general neurology

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