review part 1 (test 3) Flashcards
What are the neuclei of the basal ganglion?
Caudate
Putamen
Globus pallidus (external and internal)
Subthalamic nuclei
Substantia nigra (pars compacta and pars reticulata)
What nuclei make up the striatum?
caudate and the putamen
Describe the direct pathway of the basal ganglia
1) Cortex neurons excite neurons in the striatum via the release of glutamate
2) Striatum neurons inhibit neurons in the internal globus pallidus and substantia nigra pars reticulata
3) Inhibited neurons in GPi and SNR cannot inhibit thalamic neurons
4) Thalamic neurons excite neurons in the cortex to allow for movement
Describe the indirect pathway of the basal ganglia
1) Cortex excite neurons in the striatum via glutamate
2) Neurons in the striatum inhibit neurons in the external globus pallidus via GABA
3) Inhibited GPe neurons cannot inhibit the subthalamic nucleus
4) Subthalamic nucleis excite the internal globus pallidus and substantia nigra reticulata nuclei va glutamate
5) GPi and SNR inhibit neurons in the thalamus via GABA
6) Inhibited thalamus cannot stimulate cortex
7) No movement
What part of the substantia nigra synthesizes dopamine? How does dopamine levels influence the internal and external basal ganglia pathways?
Substantia nigra pars compacta synthesizes dopamine
direct pathway cells in the striatum have D1 (excitatory) receptors and indirect cells in the striatum have D2 (inhibitory). Increased levels of dopamine favors the direct pathway and inhibits the indirect pathway. Low levels of dopamine favors the indirect pathway
Parkinson’s is the destruction of cells in the _______. This results in overactivation of the ________ (direct/indirect) pathway.
Parkinson’s is the destruction of cells in thesubstantia nigra pars compacta. This results in overactivation of the ________ indirect pathway.
What are the cardinal motor features of parkinson’s disease?
TRAPS (First Aid mnemonic)
Tremor (usually resting tremor)
Rigidity (cog-wheel rigidity)
Akinesia/bradykinesia (hypophonia, hypomimia, micrographia)
Postural instability
Shuffling gait
Are smoking and caffeine protective factors against parkinson’s?
yes
How do you treat parkinson’s?
levadopa + carbadopa
pramipexole, ropinirole (D2 receptor agonists)
selegiline, rasagiline (MAO-B inhibitors)
Huntington’s disease is the destruction of cells in the ________ that control the ________ (direct/indirect) pathway.
Huntington’s disease is the destruction of cells in the striatum (caudate) that control the indirect pathway.
What is the clinical triad of Huntington’s disease?
Movement disorder
- Chorea
Psychiatric symptoms
- depression, irritability, psychosis
Cognitive decline
What is huntington’s chorea typicillay treated with?
tetrabenazine
how many trinucleotide repeats are required for huntington’s to be 100% penetrant?
40 CAG repeats
What is hemiballismus caused by?
Damage to subthalamic nucleus → hemiballismus (too much unwanted movement)
Pathophysiology: not enough stimulation of the substantia nigra pars reticularis, which tells the thalamus to stop stimulating the cortex → too much cortical activation via direct pathway
What symptoms would you get if you damaged the cerebellar vermis?
truncal ataxia
titubation (nodding movement of the head or body)
What symptoms would you get if you damaged the cerebellar hemispheres?
appendicular ataxia
dysmetria
dysdiadochokinesia
Define hyperkinetic and hypokinetic
hyperkinetic is characterized by excessive movement
hypokinetic is characterized by bradykinesia (slowness of movement)
What is a resting tremor?
Tremor that occurs when affected body part fully supported and relaxed
What is an essential tremor? What are the 3 types?
Broad term that encompasses a tremor with movement
postural tremor, kinetic tremor, and intention tremor
What is a postural tremor?
essential tremor
Occurs when muscles activated against gravity w/o movement
What is a kinetic tremor?
type of essential tremor
Tremor that occurs with movement of a body part (finger-to-nose test)
What is an intention tremor?
type of essential tremor
tremor that occus near the target (tremor begins when the finger gets close to touching the nose or the finger in the finger-to-nose test)
How do you treat an essential tremor?
propranolol, primidone (GABA agonist), topiramate, deep brain stimulation
EtOH improves the tremor
How is dystonia characterized?
dystonia is sustained muscle contractions that frequently cause twisting and repetitive movements or abnormal postures
What are tics?
recurrent, intermittent, stereotyped, semi-voluntary movements or sounds associated with an urge
What is tourette syndrome? Are motor and vocal tics involved?
Defined as a tic disorder > 1year in duration
combination of both motor and vocal tics
What is gene mutation in Wilson’s disease? What will serum copper, serum ceruloplasmin, 24 urine copper, and liver copper show (increase/decrease?
ATB7B gene mutation —> messed up copper transporter pump —> inability to put copper into bile —> copper builds up in brain, liver, corneas, kidneys
How does Wilson’s disease present?
asteristics
dementia
hemolytic anemia
dyskinesia
Kayser-Fleischer rings
cirrhosis –> HCC
How is Wilson’s disease treated?
D-peniclillamine and zinc (block copper uptake)
What is multiple sclerosis?
demyelinating disease that affects the CNS
What are the symptoms of multiple sclerosis
UNSULARO
INSULAR:
Intention tremor/internuclear ophtalmoplegia
Nystagmus
Scanning/slurred speech
Uthoff’s phenomenon=Uhtoff’s phenomenon describes the well known finding of a temporary production or worsening of neurological symptoms in MS patients exposed to heat, such as that from a hot shower, exercise, or a warm climate. This is thought to be due to the effect of heat on myelin (insulation sheath or covering of nerves) which results in abnormal transmission of nerve impulses
Lhermitte’s sign-flexing of neck produces electric shock sensation running down
the spine
Ataxia
Rebound/relapse
Optic neuritis
Is optic neuritis a common presentation in patients with MS?
yeah
What are the 4 different subtypes of MS?
How is a diagnosis of MS made?
diagnosis is made through space and time
MRI shows 2 lesions affecting 2 different parts of the CNS that occured at different times
What would you expect to find in the CSF of a MS patient?
oligoclonal IgG in CSF (on electrophoresis)
How do you treat an acute MS relapse?
IV solu-methylprednisolone (corticosteroids)
What are the MS drugs?
corticosteroids
interferon beta (Avonex and betaseron)
dimethyl fumerate
teriflunomide
fingolimod
mitoxantrone
natalizumab
glatiramir acetate
Which MS drug is safe for pregnancy?
glatiramer acetate
