We know that conservative treatments, such as exercise and pain education can improve the symptomatology in most cases (Wood & Hendrick, 2019). Unfortunately, in about 10-20% of these patients, conservative therapy is not enough and surgical intervention is the treatment (Gautschi et al., 2008). As we saw in our podcast episode about physiotherapy, non-specific LBP and disc herniation are very common reasons for consultation, for conservative treatments as well as for post-surgical interventions patients.
“...in about 10-20% of these patients, conservative therapy is not enough and surgical intervention is the treatment”
Gautschi et al., 2008
For this kind of study cases, we usually say that the thermal representation of LBP is very complicated to interpret and quite fluctuating depending on the severity, injury mechanism and age. But we will leave that for later, today I bring you a simple case, let us get to it.
He is a 37-year-old male patient with a history of recurrent LBP (including an episode of sciatic pain). He went to the emergency room due to extreme pain and loss of sensitivity and motricity in his entire left leg.
After a diagnosis of disabling compression (increase of pain and loss of functionality) of the L4 and L5 roots, an open lumbar microdiscectomy, a surgical intervention which has shown good clinical results (Kim et al., 2018), was the surgeon's decision.
Figure 1: open lumbar microdiscectomy’s patient after 8 weeks, seen with digital (left)
and thermal (right) vision, where we can see the path of the nerve root colder than the contralateral
As you can see on the left side of Fig. 1, the scar can be seen with the naked eye. On the right side, we can see something even more interesting. This is the region of the skin where the L4-L5 nerve root usually is placed, appears with a decreased temperature in the thermogram. This may indicate a decrease in physiological activity of the nerve. Even after a successful surgery, the patient still feels pain in his low-back (VAS 4 for the left and 8 for the right side).
When he arrives for a physiotherapy consultation (8 weeks after the surgery), he presents two main symptoms. The first one is pain in the lumbar region and , but completely functional. The second one is loss of sensitivity and motricity (4/5 strength in the dorsal flexors and evertors of the foot). This correlates perfectly with the hypothermia regions shown just below in Fig. 2, where we can also see the patient’s pain perception in the posterior lower leg, evaluated with VAS and showing significant hypothermia.
Figure 2: avatars and thermograms showing hypothermias in the regions of hyposensitivity and hypomotricity. Also VAS (Visual Analogue Scale) showing pain perception of the patient in the posterior lower leg.
The physiotherapy treatment consisted essentially on therapeutic exercise (Owen et al., 2020) and pain neuroscience education (Wood & Hendrick, 2019). Fortunately, 4 months after the surgery and 2 months after an intervention of active treatment, this patient has experienced a relevant improvement and a successful recovery.
This is one of the most important reasons why we love to use thermography with this purpose: diagnosis support and injury follow-up. Thanks to these two strategies we can have the best available information, in order to make better decisions. Besides, we can see the evolution of the treatment and, even more important, show it to the patient, so that he can see by himself if the therapy is working properly.
To sum up, in this study case, we have seen how thermography can support the diagnosis by showing the strong relationship between temperature decrease and nerve anomalies that affect the functionality (pain and motricity) of the adjacent tissues.