Can neuropathy cause a loss of sensation or reduced reflexes? 

Yes, neuropathy can cause both a significant loss of sensation and reduced or absent reflexes. These are considered negative symptoms of nerve damage, where the normal functions of the nervous system are diminished or lost entirely. In the United Kingdom, these signs are essential for clinicians when distinguishing between different types of nerve disorders. While tingling and pain are loud symptoms that get a patient attention, the silent loss of feeling and reflexes often points to more advanced or specific types of nerve fibre damage. 

When the nerves that carry messages to the brain or the nerves that trigger muscle responses are compromised, the body automatic and protective systems begin to fail. This article explores how nerve damage disrupts the reflex arc and why a loss of sensation can lead to serious secondary complications. 

What We Will Discuss In This Article 

• Sensory Loss: Why touch, temperature, and vibration fade away 

• The Reflex Arc: How nerve damage leads to areflexia 

• Large Fibre Involvement: The specific nerves responsible for reflexes 

• Clinical Significance: What a GP looks for during a reflex hammer test 

• Safety Risks: Navigating the world with reduced sensation 

• Emergency guidance for rapid loss of feeling or movement 

Understanding Loss of Sensation 

Sensory loss in neuropathy is often described as a feeling of numbness or deadness in the limbs. This happens when the sensory axons are no longer able to transmit electrical signals from the skin to the spinal cord. 

• Touch and Pressure: You may lose the ability to feel the texture of objects or the pressure of your feet hitting the ground. This is often described as walking on cotton wool. 

• Temperature and Pain: Small fibre damage can make it impossible to tell if water is scalding hot or if you have stepped on a sharp object, which significantly increases the risk of injury. 

• Proprioception: This is the loss of your body internal GPS. Without it, your brain does not know exactly where your feet are in space, leading to poor balance and a higher risk of falls. 

Why Reflexes Become Reduced or Absent 

Reflexes are the body most basic protective mechanism. A reflex, like the knee jerk, happens through a loop called the reflex arc. This arc consists of a sensory nerve that detects a stimulus and a motor nerve that tells the muscle to contract. 

Neuropathy disrupts this loop in several ways: 

1. Large Fibre Damage: The nerves responsible for reflexes are the large, myelinated fibres. If these are damaged by conditions like diabetes or CIDP, the signal is either too slow or too weak to trigger a response. 

2. Breach in the Arc: If either the sensory limb or the motor limb of the arc is damaged, the reflex will be diminished, known as hyporeflexia, or completely absent, known as areflexia. 

In the UK, an absent ankle jerk is often one of the very first clinical signs of peripheral neuropathy, appearing even before a patient notices any numbness. 

Clinical Significance and Testing 

In an NHS setting, testing reflexes is a standard part of a neurological exam. The results provide immediate clues about where the damage is located: 

• Lower Motor Neurone Signs: Absent reflexes, along with muscle wasting and weakness, suggest that the problem is in the peripheral nerves. 

• Upper Motor Neurone Signs: Conversely, overactive or brisk reflexes usually suggest an issue within the brain or spinal cord. 

Clinicians will typically test the biceps, triceps, knee, and ankle reflexes using a rubber hammer. If they cannot elicit a reflex, they may use the Jendrassik maneuverer, asking you to clench your teeth or hook your fingers together and pull, which can sometimes bring out a hidden reflex. 

Emergency Guidance 

A sudden or rapidly spreading loss of sensation and reflexes can indicate an acute neurological crisis. Seek emergency care immediately if you experience: 

• Sudden loss of feeling that moves rapidly from the feet up to the torso 

• New and total loss of reflexes accompanied by profound muscle weakness 

• Difficulty breathing or swallowing, which can occur if the neuropathy affects the chest and throat 

• Sudden loss of bladder or bowel control along with saddle anaesthesia 

• Signs of a silent heart attack such as sudden nausea and weakness without chest pain 

In these situations, call 999 or attend your nearest Accident and Emergency department immediately. 

To Summarise 

Loss of sensation and reduced reflexes are clear physical markers of peripheral nerve damage. While sensation loss increases the risk of accidental injury and falls, the loss of reflexes is a vital diagnostic tool that helps medical professionals identify the specific pathway of the damage. In the UK, these signs often point toward large fibre involvement and require investigation into causes like diabetes, B12 deficiency, or autoimmune issues. Protecting your limbs through regular checks and clinical monitoring is the best way to manage the risks associated with these quiet symptoms. 

Authority Snapshot 

This article was reviewed by Dr. Rebecca Fernandez, a UK trained physician with an MBBS and extensive experience in internal medicine, surgery, and emergency care. Dr. Fernandez has managed critically ill patients and stabilized acute trauma cases, providing her with the expertise to recognize the clinical red flags of reflex failure and sensory deficit. Her background in evidence based psychiatry and digital health ensures a holistic perspective on managing both the physical risks and the mental health impact of living with a sensory coordination disorder.