Neurology · MU Sofia

4. Sensation: study of common sensation, sensory symptoms, sensory syndromes

Covers how common sensation is examined with eyes closed and compared side to side, dividing testing into superficial sensibility (touch, pain, temperature) and deep sensibility (position, vibration, pressure). It then lists cortical sensory tests such as stereognosis and graphesthesia, followed by positive and negative sensory symptoms with their definitions. The note closes with six sensory syndromes, including peripheral nerve, polyneuropathy, radicular, spinal cord, thalamic and cortical patterns, with their features and examples.

Inside: 1 section · 16 flashcards · 2 min

Topic 4 of 88 in the MU Sofia syllabus for Neurology (Medicine, Year 4). The free AceMed note covers it in 1 section, about 330 words (2 min of reading), with 16 flashcards.

In this note

  1. Sensation - study of common sensation, sensory symptoms, sensory syndromes.

Sensation - study of common sensation, sensory symptoms, sensory syndromes.

Study (Examination) of Common Sensation

The patient should have closed eyes and be compared bilaterally.

1.Superficial Sensibility

  • Touch: cotton wool or tissue
  • Pain: pin or neurotip (sharp/blunt discrimination)
  • Temperature: warm and cold objects

2.Deep Sensibility "PVP"

  • Position sense: movement of fingers or toes up/down
  • Vibration sense: 128-Hz tuning fork over bony prominences
  • Pressure sense: pressure applied to muscles/tendons

Cortical Sensory Functions

(Tested only if superficial and deep sensation are intact)

1.Stereognosis: identification of an object by touch

2.Graphesthesia: recognition of numbers/letters drawn on skin

3.Two-point discrimination

4.Barognosis: recognition of object weight

Sensory Symptoms

1.Positive Symptoms (Irritative)

Abnormal sensations experienced by the patient.

  • Paresthesia: Abnormal sensation without stimulus. Tingling. Pins and needles. Prickling
  • Dysesthesia: Unpleasant abnormal sensation, spontaneous or evoked.
  • Hyperesthesia: Increased sensitivity to stimulation.
  • Hyperalgesia: Exaggerated pain response to a painful stimulus.
  • Allodynia: Pain caused by a normally non-painful stimulus.
  • Neuralgia: Pain along the course of a nerve.

2.Negative Symptoms (Loss of Sensation)

  • Anesthesia: Complete loss of sensation.
  • Hypesthesia: Partial reduction of sensation.
  • Analgesia: Loss of pain sensation.
  • Thermoanesthesia: Loss of temperature sensation.
  • Loss of Proprioception: Impaired position and vibration sense causing sensory ataxia.

Sensory Syndromes

1. Peripheral Nerve Syndrome::Sensory loss follows the distribution of a specific nerve.

  • Features: Pain. Paresthesias. Hypesthesia/anesthesia. Weakness may coexist
  • Example: Median nerve neuropathy.

2. Polyneuropathy Syndrome: Symmetrical distal sensory impairment.

  • Features: "Glove and stocking" distribution. Paresthesias. Reduced reflexes. Distal weakness
  • Common causes: Diabetes mellitus. Alcoholism. Vitamin B12 deficiency

3. Radicular Syndrome: Damage to spinal nerve roots.

  • Features: Sharp shooting pain. Dermatomal sensory loss. Reduced corresponding reflexes
  • Example: Lumbar disc herniation.

4. Spinal Cord Sensory Syndromes: Posterior Column Syndrome

  • Loss of: Vibration sense. Position sense. Discriminative touch
  • Results in: Sensory ataxia. Positive Romberg sign. Spinothalamic Syndrome
  • Loss of: Pain. Temperature. Usually contralateral below the lesion.

5. Thalamic Syndrome: Lesion of the thalamus.

  • Features: Contralateral sensory loss
  • Severe spontaneous pain (thalamic pain). Hyperesthesia

6. Cortical Sensory Syndrome: Parietal lobe lesion.

  • Features:. Astereognosis (cannot identify objects by touch). Agraphesthesia. Impaired two-point discrimination

Primary sensations remain relatively preserved.

Read the full note free

The whole note is free with an AceMed account, with its 16 flashcards. Premium adds flashcard recall, highlights and Ask AI.

Start freeAlready a member? Open the note