Neurological infective and degenerative disease talk to ancillary - Dr Patel (4).pptx

Neurological infective and degenerative disease Sensory + Motor homunculus  Management consultant The extrapyramidal and spinocerebellar systems serve to modulate and fine tune all outputs and evaluate and adjust depending on feedback so that the desired outcome is ach...

Neurological infective and degenerative disease Sensory + Motor homunculus  Management consultant The extrapyramidal and spinocerebellar systems serve to modulate and fine tune all outputs and evaluate and adjust depending on feedback so that the desired outcome is achieved. The cerebellum allows learning and adjustment (together with the cortex) The extrapyramidal system (basal ganglia, red nuclei, premotor cortex, reticular formation, sub-thalamic nuclei) also influences output from the cortex via feedback loops and instruction to the AHC via reticulo-spinal fibers.  Supplementary motor area (programme) Motor cortex Sensory cortex Basal ganglia, cerebellum thalamus F e Brainstem e d b a Spinal cord, descending tracts Spinal cord, ascending tracts c k Peripheral nerve Anterior horn cell Peripheral nerve, muscle Sensory receptors -cutaneous -muscle spindle -golgi tendon organs Action -propioceptors -visual, vestibular  Threats to the system Dysfunction can come from: – direct damage to CNS – peripheral structures – compression by unwanted structures such as blood clots, tumors, bone displacement – infarction with swelling, infection, degeneration etc. – Trauma – Altered blood supply, altered blood content  Threats to the system Ischemia Tumours in the brain or spinal cord metabolic abnormal brain chemistry, acidosis, hypoglycemia, hypoxia, electrolyte abnormalities, toxins abnormal circuits - result in epilepsy, movement disorders, psychosis Neurodegenerative disease Parkinsons disease, Cerebellar ataxia Chorea, muscular dystonia/dystrophy  Parkinsons disease Neurodegenerative disease characterised by Lewy body accumulation in areas of the body resulting in dysfunction Recent data suggest that abnormality also occurs outside the CNS e.g. the myenteric plexus Classical degeneration in Substantia nigra pars compacta H&E stain demonstrating a lewy body with the accumulation of neurofilaments Step 1: Diagnosis of parkinsonism Bradykinesia and at least one of the following: Muscular rigidity 4-6 Hz resting tremor Postural instability not caused by primary visual, vestibular, cerebellar or proprioceptive dysfunction Balance, tone would be areas to address  Cerebellar Ataxia Cerebellar ataxia (from the Greek words “a,” meaning “not,” and “taxis,” meaning “order”) is characterized by an incoordination of movement and unsteadiness due to cerebellar dysfunction. Clinical examination characterised by variability in amplitude: – reveals a gait disorder with imbalance, staggering – difficulties with tandem walking – upper-limb and lower-limb dysmetria, dysdiadochokinesia (difficulty performing rapidly alternating movements) – hypotonia, cerebellar dysarthria, and saccadic ocular pursuit  Ataxia: management If etiology found treat Otherwise symptomatic therapy: – Difficult to treat – Physical measures such as walkers, weights etc. In MS patients DBS has some benefit. Experimental  Definition: chorea/ballismus Chorea is characterised by irregular, rapid, non stereotyped, random, involuntary movement; when subtle may just manifest as fidgetiness or restlessness in children Ballismus is proximal chorea resulting in large amplitude movements. Usually seen with lesion of the subthalamic nucleus, but can occur from lesions along all its afferent or efferent paths. Classified according to aetiology Therapy relates to aetiology and symptomatic therapy usually the butoryphenones such as haloperidol. Anti-epileptic such as valproate and benzodiazepines may be tried Neuroanatomy and neurophysiology of chorea Chorea results from dysfunction within a complex neuronal network interconnecting motor cortical areas and a group of subcortical nuclei collectively termed the basal ganglia. The latter include the caudate nucleus, putamen, external and internal segments of the globus pallidus (GPe and GPi) as well as associated structures such as the subthalamic nucleus and the substantia nigra  Chorea: disease Huntingtons Sydnehams chorea – AD, 10/100000 – Usually in childhood – Chr 4, codes for – Major criterion for huntingtin, rheumatic fever neurotoxic gain of – Increased Group A function – May have beta hemolytic psychiatric or streptococcus titer movement – Usually remits disorder within 15 weeks but – In adolescence can recur have – Treat parkinsonism symptomatically – Associated with with haloperidol caudate atrophy and provide – depression is prophylaxis for common rheumatic fever  Definition: dystonia Dystonia is characterized by involuntary sustained contraction of muscles or groups of muscles resulting in an abnormal posture. It may be associated with a tremor. Classification: – Age related: Early onset : 26 years – Distribution: Focal Segmental Multifocal Hemi-dystonia Therapy botulinum toxin Weakness  UMN and LMN UMN LMN – Weakness – Weakness – No wasting – Reduced tone – Increased tone – Reduced or absent (spastic) reflexes – Brisk reflexes – Wasting of muscles – Extensor plantar responses  UMN & LMN Causes UMN LMN – Brain lesions – AHC (polio, SMA, (stroke, tumour, AVM) haemorrhage, – Root (disc disease, demyelination, arachnoiditis, AIDP, ADEM) CIDP) – Spine (fracture with – Plexopathies spine impression, – Peripheral tumour, neuropathy demyelination, viral – Myopathies myelitis, B12 – Myoneural junction deficiency) (myasthenia gravis)  Muscular dystrophies Many causes of muscular dystrophy Pattern of weakness defines type – Duchenes muscular dystrophy (dystrophinopathy) – Limb girdle muscular dystrophy (many types) – Congenital myopathy (may types) – Myotonic dystrophies (dystrophia myotonica, schwartz Jampel) Most are genetically determined Therapy usually supportive: – OT, physiotherapy Infections, polio, GBS, Abscess, meningitis, encephalitis  Polio Poliomyelitis is inflammation of the grey matter usually of the spinal cord where the AHC resides Caused by polio or other viruses (CMV, herpes, entero-viruses) Characterised by LMN features and no sensory abnormality Therapy supportive  AIDP (GBS) Acute inflammatory demyelinating poly-neuropathy May have an antecedent infection. Viral, TB, Campylobacter. Jejuni Association with SLE May be limited to limbs or progress to include respiratory and bulbar muscles requiring support  AIDP (Guillain Barre) Lower motor neuron disease Demyelination of nerve roots and peripheral nerves Acute weakness which can progress rapidly Usually symmetrical weakness with bladder function spared Treat with – observation – IVIG – Support if requires ICU care and ventilation – Physiotherapy, occupational therapy  Brain abscess Pimple in the brain Can be by haematogenous spread (infective endocarditis) or contiguous spread (sinus disease, middle ear disease) Multiple organisms, M.tb. Treatment with antibiotics and drainage if appropriate  Meningitis Inflammation of the covering of the brain Pathogenesis: hematogenous spread, contiguous spread Cause by bacteria (meningococcus, pneumococcus, staphylococcus, M.tb.), fungi (cryptococcus, candida), spirochete (syphilis), parasites (cysticercus), virus (HIV, influenza) Headache, neck stiffness and confusion are cardinal features Treat cause and complications (abscess, infarction, hydrocephalus, raised intracranial pressure, depressed level of consciousness)  M.Tb. Cryptococcus neoformans Listeria Monocytogenes T. Pallidum Neisseria meningitides  Encephalitis Inflammation of the brain itself Common cause herpes simplex. Other viruses (HIV, CMV, Zoster), paraneoplastic disease These patients tend to be confused Therapy supportive and antibiotics (for herpes or CMV)  meningoencephalitis Inflammation of the meninges and brain tissue Confusion, neck stiffness Causes many (bacteria, viruses, parasites, malignancy , paraneoplastic disease)