Brachial Neuritis Flashcards
Describe what is meant by brachial neuritis [1]
What is typical presentation? [1]
Rare condition that affects the brachial plexus nerves in the shoulder and upper arm.
- It typically presents with sudden onset severe pain followed by weakness and atrophy of the affected muscles.
NB: The exact cause of brachial neuritis is unknown, but it is thought to be related to an autoimmune response triggered by infection or trauma.
Describe the clinical features of brachial neuritis [2]
acute, severe pain in the shoulder region
- udden onset and may be preceded by an antecedent event such as infection, surgery, or trauma
- many cases have no identifiable precipitating factor
- sharp or burning nature
- exacerbated by movement
Following the initial phase of intense pain, which can last from hours to weeks, patients may experience progressive weakness and atrophy in one or more muscles innervated by the brachial plexus.
Sensory disturbances are less common but can manifest as numbness, tingling (paresthesia), or altered sensation (dysesthesia) in areas corresponding to affected nerves
Describe the difference between Erb-Duchenne and Klumpke’s paralysis [2]
Erb-Duchenne paralysis
* damage to C5,6 roots
* winged scapula
* may be caused by a breech presentation
Klumpke’s paralysis
* damage to T1
* loss of intrinsic hand muscles
* due to traction
Describe the pathophysiology [1] and clinical features [5] of cervical spondylitic myelopathy
Pathophysiology:
- Cervical spondylosis is a degenerative condition affecting the cervical spine, essentially osteoarthritis of the cervical vertebral bodies. If the spinal canal is narrowed due to this process it can press on the spinal cord resulting in neurological dysfunction.
Features:
* a variety of motor weakness, sensory loss and bladder/bowel dysfunction may be seen
* neck pain
* wide-based, ataxic or spastic gait
* upper motor neuron weakness in the lower legs - increased reflexes, increased tone and upgoing plantars
* bladder dysfunction e.g. urgency, retention
An [] of the cervical spine is the gold standard test where cervical myelopathy is suspected. It may reveal [3]
An MRI of the cervical spine is the gold standard test where cervical myelopathy is suspected. It may reveal disc degeneration and ligament hypertrophy, with accompanying cord signal change.
Should be referred for assessment by specialist spinal services (neurosurgery or orthopaedic spinal surgery).
Early treatment (within 6 months of diagnosis) offers the best chance of a full recovery but at present, most patients are presenting too late
- decompressive surgery is the only effective treatment. It has been shown to prevent disease progression.
Describe the age of onset of FTD [1]
FTD is a common cause of early onset dementia (< 65 years old):
- mean age of onset is 58 years old
Describe the pathophysiology of FTD
Characterised by tissue deposition of aggregated proteins including phosphorylated tau or transactive response DNA-binding protein 43 (TDP-43).:
- Tau is the major protein of ‘Pick bodies’ that may be seen in certain pathological subtypes
MRI or CT shows symmetrical atrophy predominantly affecting the frontal and/ or temporal lobes
FTD is strongly genetically linked.
Name three genes which are linked to FTD [3]
MAPT:
- Leads to a propensity of tau to form neurotoxic aggregates
Granulin precursor - GRN:
C9ORF72 gene: found on chromosome 9. Most common genetic cause of inherited FTD. Also implicated in hereditary motor neuron disease. Usually results in bvFTD with or without MND.
Describe the different symptomatic classifications of FTD [3]
Behavioural variant Frontotemporal Dementia (bvFTD):
- Most common form
- changes in personality and behaviour, including disinhibition, apathy, loss of empathy or compulsive behaviours
Semantic Dementia (SD):
- loss of semantic knowledge - patients have difficulty understanding words or recognising familiar people or objects
Progressive Nonfluent Aphasia (PNFA):
* Characterised by progressive language disorder with non-fluent speech and grammatical errors.
* Patients may also show signs of agrammatism or apraxia of speech.
Describe the different neuropathological classifications of FTD [3]
Tau-positive FTLD:
- tau proteins accumulate abnormally within neurons leading to neurofibrillary tangles.
- Three major types exist based on the morphology and distribution of tau inclusions: Pick’s disease, corticobasal degeneration, and progressive supranuclear palsy.
TDP-43 positive FTLD:
- Characterised by the accumulation of transactive response DNA binding protein 43 (TDP-43).
- Four subtypes exist (A to D) based on the distribution and morphology of TDP-43 inclusions.
FUS-positive FTLD:
- Less common, characterised by the presence of fused in sarcoma (FUS) protein within inclusion bodies
- These are typically seen in younger patients and often associated with a more aggressive disease course.
PM
What are the three recognised types of FTLD? [3]
There are three recognised types of FTLD
Frontotemporal dementia (Pick’s disease)
Progressive non fluent aphasia (chronic progressive aphasia, CPA)
Semantic dementia
Describe the clinical features of FTD
Behavioural changes:
* Disinhibition (e.g. socially inappropriate behaviour)
* Loss of empathy
* Apathy (losing interest and/or motivation)
* Hyperorality (e.g. dietary changes, attempt to consume non-edible products, eat beyond satiety)
* Compulsive behaviour (e.g. cleaning, checking, hoarding)
Primary progressive aphasia
* Language difficulty as the predominant feature
* Aphasia
* Decrease in speed of speech
* Difficulties with comprehension
* Syntax
* Object naming
Decline in executive functioning and cognition
* Difficulty planning
* Poor concentration
Motor syndromes
NB: An important aspect of the presentation is that behaviour or speech changes are noticed prior to memory problems and this can help distinguish it from other dementias
What is a key distinguishing feature of FTD that helps seperate it from other dementias? [1]
An important aspect of the presentation is that behaviour or speech changes are noticed prior to memory problems
Describe the typical features in neuroimaging of bvFTD; nonfluent PPA; semantic PPA [3]
bvFTD:
- frontal and temporal atrophy in up to 65%. Particularly anterior insula, anterior cingulate cortex, and amygdala. May be asymmetrical.
Nonfluent PPA:
- early atrophy and hypoperfusion in the left posterior fronto-insular cortex.
Semantic PPA:
- significant anterior temporal atrophy. Often asymmetric.
Describe the treatment for FTD [1]
Unfortunately, there are no disease modifying treatments that can be used in FTD. Management focuses on treatment of behaviour and cognitive decline. This may require pharmacological intervention, but it does not alter the disease progression.
Which drug / class should be avoided in FTLD? [2]
Acetylcholinesterase inhibitors or memantine hydrochloride are not recommended in patients with FTLD.
How would you differentiate frontotemporal lobar degeneration with:
AD [2]
Vascular Dementia [2]
Alzheimer’s disease (AD)
Similarities:
* Loss of apathy
* Subtle personality changes and loss of interest in daily activities
* Grossly unremarkable physical exam
Differences:
* Memory loss predominates in AD
* CT brain shows global atrophy in AD
Vascular dementia
Similarities:
* Loss of apathy
* Loss of executive functions
* Impulsivity and irritability
* Relative preservation of memory
Differences:
* Presence of cardiovascular risk factors
* CT brain will show evidence of infarcts
What are the similarities / differences of FTD and DLB [2]
Dementia with Lewy bodies (DLB)
Similarities:
* Loss of apathy
* Cognitive fluctuations
Differences:
* Visual hallucinations and motor signs are key features in DLB
* Personality is relatively preserved
Pharmacological therapies - these should only be used if non-drug therapies have failed
Which drugs could be used? [3]
Pharmacological therapies - these should only be used if non-drug therapies have failed.:
* Benzodiazepines - for acute agitation and distress.
* SSRIs - for associated depression, anxiety, irritability and disinhibition.
* Antipsychotics - very low doses should be used and as a last resort.
* Oxytocin - emerging evidence suggests this may help with improving empathy but is not yet approved.
NB: Acetylcholinesterase inhibitors or memantine hydrochloride are NOT recommended in patients with FTLD.
