Neurological Disorders and Pain Mechanisms

Thalamic Pain Syndrome, or central post-stroke pain, is characterized by contralateral sensory loss, hemi-ataxia, and severe spontaneous burning pain.

Sensory ataxia is due to loss of position sensation, while cerebellar ataxia results from lesions in the neocerebellum.

Peripheral neuropathy leads to sensory loss in affected areas; mononeuropathy affects one nerve, whereas polyneuropathy involves multiple nerves, often causing 'glove and stocking' sensory disturbances.

<p>Herpes Zoster occurs when the herpes virus attacks a dorsal root ganglion, causing severe pain and a painful skin rash in the associated dermatomal segment.</p> Signup and view all the answers

<p>Neuropathic pain is a chronic pain arising from damage to nerve fibers, often described as burning or electric; examples include trigeminal neuralgia and diabetic neuropathy.</p> Signup and view all the answers

<p>Sensory cortical lesions do not completely abolish somatic sensations, indicating some degree of sensory function remains.</p> Signup and view all the answers

<p>Diabetic neuropathy typically presents with 'glove and stocking' sensory disturbances, affecting distal areas of the limbs.</p> Signup and view all the answers

<p>Neuropathic pain is characterized by specific sensations such as burning or tingling, and it often occurs in paroxysms along with hyperalgesia and/or paresthesia.</p> Signup and view all the answers

<p>At the level of the lesion, there is flaccid paralysis and loss of all reflexes on the same side, along with loss of all sensations at the corresponding dermatome.</p> Signup and view all the answers

<p>Below the lesion, there is loss of fine touch, pressure, and vibration sensation due to dorsal column damage, along with spastic paralysis and hyper-reflexia from corticospinal tract damage.</p> Signup and view all the answers

<p>On the opposite side, there is a loss of pain and temperature sensations due to the lesion in the crossed spinothalamic tract.</p> Signup and view all the answers

<p>The lateral zones of the cerebellum plan and time movements by receiving impulses from cortical association areas, coordinating the progression from one movement to the next.</p> Signup and view all the answers

<p>Ataxia is characterized by incoordination of movements, resulting from errors in the rate, range, force, and direction of movement due to cerebellar lesions.</p> Signup and view all the answers

<p>Areflexia involves the interruption of the reflex arc, which can be caused by peripheral neuritis or tabes dorsalis.</p> Signup and view all the answers

<p>Lesions in the cerebellar cortex lead to temporary movement abnormalities that may compensate over time, while lesions in the cerebellar nuclei produce permanent and generalized defects.</p> Signup and view all the answers

<p>The corticospinal tract is responsible for voluntary motor control, and its damage leads to spastic paralysis, while the spinothalamic tract affects pain and temperature sensations, causing loss on the opposite side of a spinal cord injury.</p> Signup and view all the answers

<p>It compares intended movements with actual movements and initiates corrective signals to the motor cortex.</p> Signup and view all the answers

<p>Hyporeflexia is a decreased reflex response due to interruption of facilitatory impulses; it can be caused by neocerebellar syndrome and myxoedema.</p> Signup and view all the answers

<p>The rebound phenomenon refers to the inability to stop movement promptly when resistance is removed, causing the limb to fly backward.</p> Signup and view all the answers

<p>Intention tremor is characterized by oscillations that occur during voluntary movements, while resting tremors occur when limbs are at rest.</p> Signup and view all the answers

<p>It transmits information about commands from the motor cortex to the cerebellum, facilitating adjustments to muscle activity.</p> Signup and view all the answers

<p>Hypereflexia involves exaggerated reflex responses due to upper motor neuron lesions, while hyporeflexia entails diminished responses from interrupted facilitatory impulses.</p> Signup and view all the answers

<p>Dysmetria is the inability to properly gauge distances in movement, often assessed using the finger-nose test which reveals overshooting.</p> Signup and view all the answers

<p>Common signs include a wide-based, unsteady gait and tilting of the head toward the side of the lesion.</p> Signup and view all the answers

<p>Adiadochokinesia is the inability to perform rapidly alternating opposite movements, such as repeated pronation and supination of the hands.</p> Signup and view all the answers

<p>Decomposition of movements refers to the difficulty in performing actions that involve simultaneous motion at more than one joint.</p> Signup and view all the answers

<p>The types of sensory losses include loss of fine touch, stereognosis, proprioceptive sensations, and some pain localization but with mild effects on pain sensation.</p> Signup and view all the answers

<p>Nystagmus is characterized by tremors of the eyeball when attempting to fix gaze laterally, often due to lack of damping function.</p> Signup and view all the answers

<p>Syringomyelia is a condition characterized by the widening of the central canal in the spinal cord, affecting pain, temperature, and crude touch sensations due to damage to crossing fibers.</p> Signup and view all the answers

<p>Hypotonus refers to decreased muscle tone on the side of the lesion, resulting in diminished stretch reflexes.</p> Signup and view all the answers

<p>The cerebellum functions as a servo-comparator that assists in planning and timing voluntary movements.</p> Signup and view all the answers

<p>Tabes dorsalis leads to degeneration of sensory nerves causing loss of vibration and proprioceptive senses, resulting in incoordination and ataxia.</p> Signup and view all the answers

<p>Primary hyperalgesia is an exaggerated pain response in injured or inflamed skin, caused by the sensitization of peripheral nociceptors by inflammatory mediators.</p> Signup and view all the answers

<p>The cerebellum maintains equilibrium via input from the vestibular apparatus, modulating tone in axial and girdle muscles.</p> Signup and view all the answers

<p>Secondary hyperalgesia occurs in uninjured skin and is due to sensitization of central pain neurons, which leads to prolonged and severe pain when the pain threshold is reached.</p> Signup and view all the answers

<p>Muscle tone is based on static stretch reflex and is essential for maintaining body posture against gravity.</p> Signup and view all the answers

<p>Muscle tone does not cause fatigue due to the subtetanic contraction of different muscle fibers alternating in use.</p> Signup and view all the answers

<p>'Dissociated sensory loss' refers to the preservation of dorsal column sensations, such as fine touch, while there is loss of pain and temperature sensations.</p> Signup and view all the answers

<p>Patients with sensory ataxia typically exhibit a high steppage gait and a positive Romberg's sign, indicating loss of proprioceptive input.</p> Signup and view all the answers

<p>Amorphosynthesis, or neglect syndrome, refers to the failure to perceive or respond to stimuli on the contralateral side of the body due to lesions in sensory areas of the cortex.</p> Signup and view all the answers

<p>The main manifestations include ataxia, disturbance of posture and gait, dysmetria, intention tremor, adiadochokinesia, slurred speech, and nystagmus.</p> Signup and view all the answers

<p>The neocerebellum facilitates the stretch reflex by prolonging its effect, aiding in posture maintenance.</p> Signup and view all the answers

<p>Muscle spindles assist in smooth muscle contractions through feedback adjustments and prevent oscillatory movements.</p> Signup and view all the answers

<p>The cerebellum inhibits the motor cortex to precisely time muscle movements, allowing for corrections to stop at the intended point.</p> Signup and view all the answers

<p>Damage leads to symptoms like ataxia and disturbances in posture and gait, affecting coordination on the same side as the lesion.</p> Signup and view all the answers

<p>The stretch reflex helps to maintain muscle length and control voluntary movements, essential for muscle tone.</p> Signup and view all the answers

<p>Adiadochokinesia is an inability to perform rapid alternating movements, often observed in patients with cerebellar lesions.</p> Signup and view all the answers

<p>It provides inhibitory impulses to control and fine-tune muscle actions after they begin, ensuring smooth and accurate movements.</p> Signup and view all the answers