Speech Problems

 

• Dysphasia

  Overview:

  • A deficit in the higher language functions i.e. comprehension and generation.
  • Aphasia is a total absence.
  • Most commonly due to a left anterior circulation stroke.
  • If speech is internally consistent but nonsense, it is confusion not dysphasia.

  Receptive (Wernicke's) dysphasia

  • Temporal lobe lesion.
  • Patient can't follow a command e.g. lift a hand. If the problem is only with a series of commands, the more they can manage then the better the prognosis.

  Expressive (Broca's) dysphasia

  • Frontal lobe lesion.
  • Can't generate speech.

  Nominal aphasia

  • Dominant posterior temporo-parietal lesion.
  • Difficulty in recalling specific words or names, but rest of speech normal.
  • Patient may not be able to name specific objects shown to them.

  Conduction dysphasia

  • Longitudinal fasciculus lesion.
  • Patient can understand and speak, but can't repeat a phrase.

• Dysarthria

  • Poor articulation.
  • Causes: bulbar or pseudobulbar palsy, or (less commonly) facial nerve palsy.
  • Examination: test tongue (say la la la) and palate (ka ka ka) for bulbar function, and lips (ma ma ma) for facial nerve function.

• Dysphonia

  • Reduced speech volume due to weak respiratory muscles or vocal cords.
  • Causes: (pseudo)bulbar palsy, myasthenia gravis, Parkinson's, recurrent laryngeal nerve invasion.

• Bulbar and pseudobulbar palsy

  • The 'bulb' refers to the medulla, and bulbar palsy is dysfunction of the cranial nerves – 9 to 12 – whose nuclei lie within it.
  • It presents with dysphonia, dysarthria, and/or dysphagia.

  Bulbar palsy

  LMN lesion of the medulla (nuclei) or cranial nerve fibres.

  Causes:

  • Brainstem stroke or tumour.
  • MND, especially progressive bulbar palsy.
  • Guillain Barré.
  • Myasthenia gravis.
  • Central pontine myelinolysis.
  • Iatrogenic: surgery, radiotherapy.

  Distinguishing features:

  • Fasciculating tongue which may sit in one side of the mouth.

  Pseudobulbar palsy

  UMN lesion of the corticobulbar tract. Commoner than bulbar palsy.

  Causes:

  • Stroke e.g. of the bilateral internal capsule.
  • MS
  • Progressive supranuclear palsy
  • MND
  • Tumours higher in the brainstem.
  • Syphilis

  Distinguishing features:

  • Bilateral defects.
  • Paralysed tongue with donald duck speech.
  • Also non-bulbar symptoms – as corticobulbar tract supplies all motor cranial nerves – including hyperreflexia (jaw jerk, gag) and facial paralysis.
  • Emotional lability.