Decreased knee and ankle reflexes

Introduction Knee and sacral reflexes are clinical manifestations of lumbosacral neuritis. An abnormality of sputum reflex is a method called neuropathological abnormal reaction. It is often caused by sciatic nerve damage, lumbar disc herniation, sciatic neuritis, and sacral nerve palsy when the sacral reflex is weakened or disappeared, that is, abnormal sputum reflex, which is used for clinical examination and diagnosis. This reflection is a physiological reflex, often accompanied by a hernia when hyperpolarization, suggesting a pyramidal lesion. When the sciatic nerve is damaged, the lumbar disc is prolapsed, the sciatic neuritis, and the sacral nerve are paralyzed, the tendon reflex is weakened or disappeared.

Cause

Etiology: the afferent nerve is the phrenic nerve, the center is in the sputum 1-2, and the efferent nerve is the phrenic nerve. This reflection is a physiological reflex, often accompanied by a hernia when hyperpolarization, suggesting a pyramidal lesion. When the sciatic nerve is damaged, the lumbar disc is prolapsed, the sciatic neuritis, and the sacral nerve are paralyzed, the tendon reflex is weakened or disappeared.

an examination

Related inspection

Spinal MRI

Diagnosis: The patient was in supine position, the knee flexed and abducted, and the examiner held the patient's toes and made a slight dorsiflexion, slamming the Achilles tendon. Another method is that the patient squats on the chair and the two feet are suspended. The examiner uses the left hand to hold the foot to gently dorsiflexion and slams the Achilles tendon, or the seat is suspended from the two feet, so that the patient has a slight dorsiflexion and slams the Achilles tendon. The advantage of these methods is that the muscles are easy to detect and facilitate the extraction of reflection.

Differential diagnosis

Differential diagnosis:

(1) Sciatic neuritis: Most of the lower extremities are radioactive pain, more common on one side, acute or subacute onset, may have a history of cold or cold. Pain is often found in the buttocks and thighs, persistent pain is aggravated, increased when coughing and sneezing, and Achilles tendon reflexes (also known as tendon reflexes) weaken or disappear. The range of sensory disturbances is relatively significant, and lumbar dyskinesia is less severe. Accompanied by fever, increased blood sedimentation and so on. There is a slight loss of sensation on the lateral side of the foot and the outside of the calf.

(B) lumbosacral neuritis: more common in the middle-aged, mainly for the waist, buttocks and often radiate to the lower limbs of pain. The waist and lower limbs are restricted in activity. The pain can be aggravated by coughing, sneezing and abdominal pressure. There is weakness in one side of the pelvic and lower limbs, feelings are reduced, and knee and tendon reflexes are reduced or disappeared. One or both sides of skeletal neuralgia are also common. Complete lumbosacral plexus damage is rare, manifested as complete paralysis of one lower limb, sensory disturbance around the anus and the entire lower extremity, and may have symptoms of autonomic dysfunction such as dry skin, edema, and vasomotor disorders.

(3) Lumbar disc herniation: It often occurs in young and strong years, and males are significantly more than females. There is a history of trauma, low back pain and radiation pain in the lower extremities. Lower extremity pain can occur at the same time as the waist. Most of them are unilateral lower extremity pain, and a few are bilateral lower extremity pain or alternating pain. Pain from the buttocks through the posterolateral thigh to the lower leg or foot. Coughing and sneezing have lower limb pain, and the pain is aggravated when walking. There is obvious tenderness point next to the corresponding spinous process in the protruding part. The straight leg raising test is positive, and the affected side Achilles tendon reflex is weakened or disappeared.

(D) neurogenic muscle atrophy: onset more common in young people, more men than women, more with a family history. The main symptoms are various sensory disturbances and muscle atrophy below the junction of the lower third of the lower extremity. The numbness or paresthesia is abnormal, and the arched foot appears. In rare cases, the first onset of the hand or the simultaneous onset of the hand and foot, vasomotor dysfunction. The lower limbs are atrophied due to muscle atrophy, and the knee tendon reflex is weakened or disappeared, and the Achilles tendon reflex disappears.

(5) Diabetic polyneuritis: There is a history of diabetes. In most patients, the symptoms of peripheral neuropathy are obvious. The initial symptoms are paresthesia of the lower limbs, severe limb pain, numbness, burning sensation, etc., followed by weakness of the lower limbs, and complete paralysis is rare. The reflection disappears. The distal part of the limb has pain, temperature, touch and tuning of the tuning fork. The positional dysfunction of the joint is severe, and the ataxia may occur. The disease is more common in the elderly, especially those whose diabetes is not adequately controlled.

(6) hypothyroidism: mainly cerebellar ataxia, nystagmus, explosive language, gait instability, and some can cause spinal cord damage, lower extremity paraplegia, sensory disturbances and sphincter dysfunction. Symptoms of the distal extremities, such as tingling, numbness, burning sensation. Muscle weakness and low muscle tone, no obvious muscle atrophy. After muscle contraction, it tends to relax quickly and the relaxation period is delayed, showing a delay in sputum reflex, especially the Achilles tendon reflex and biceps reflex decline or disappear. The change in reflection is a very important sign. There can also be hallucinations, delusional states, or personality changes.

Diagnosis: The patient was in supine position, the knee flexed and abducted, and the examiner held the patient's toes and made a slight dorsiflexion, slamming the Achilles tendon. Another method is that the patient squats on the chair and the two feet are suspended. The examiner uses the left hand to hold the foot to gently dorsiflexion and slams the Achilles tendon, or the seat is suspended from the two feet, so that the patient has a slight dorsiflexion and slams the Achilles tendon. The advantage of these methods is that the muscles are easy to detect and facilitate the extraction of reflection.

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